High LTFT's and Hesitation

[BudUMfan]

At least they're trying something! Hope it's figured out soon.

[fjames]

It seems plausible that your symptoms would fit a weirdly high MAF reading, so maybe you (or the guy, but that would be scary if a service guy didn't automatically know what a normal idle V should be) got it backward and you'll be all fixed up

[Silver Ecstasy]

Yeah for sure. I can't imagine why the O2 sensor would be bad either, unless the raw fuel I wasn't burning fouled the plug up a little bit (when I cleaned my MSCAI and it was hesitating FOR REAL, not like this kind of hesitation where it's so subtle yet you feel the car slowing. That time, the car was bucking hardcore).

Either way, we're slowly but surely working on it. And my Cobb SRI and TIP will be going on the car real soon. I'm not digging the stock airbox ROFL.

Yeah we will definitely see! I can only hope. I'm also considering installing Denso ITV22's in the car to see if that fixes anything.

Otherwise, i'm stuck with this being a mechanical issue (floating brake caliper that keeps engaging? I had a rock get stuck in it back in October).

When the car's on the lift, how do you test the Limited Slip Diff? Arn't the wheels supposed to rotate opposite of one another when the car is in neutral?

[FORZDA 1]

Originally Posted by Silver Ecstasy .......When the car's on the lift, how do you test the Limited Slip Diff? Arn't the wheels supposed to rotate opposite of one another when the car is in neutral?

The fronts will rotate opposite as it is an "open" diff. The rears will rotate together as it has the LSD.

[Silver Ecstasy]

See, when I was rotating the wheel, they'd start spinning opposite, or not spin at all.

I had the driver's side cv boots replaced and I got nervous that they didn't re-install everything properly. After leaving and hearing a HORRENDOUS grinding, it turned out they didn't tighten the hub bolts? I don't know...trying to eliminate any possibilities. They've been real helpful for me, but also been real loose in their quality of service..

[fjames]

Originally Posted by FORZDA 1 The fronts will rotate opposite as it is an "open" diff. The rears will rotate together as it has the LSD.

We could only dream

[FORZDA 1]

Originally Posted by fjames We could only dream

Damn! This is the "3" section. You guys are screwed! lol

[Silver Ecstasy]

LOL. Damnit.

So seriously, how do you check? No one knows? Google searching was useless as there's so many different LSD's and methods.

[FORZDA 1]

Originally Posted by Silver Ecstasy LOL. Damnit. So seriously, how do you check? No one knows? Google searching was useless as there's so many different LSD's and methods.

Ok, according to the Mazda documentation, the Speed3 has "A Super-LSD cone-type limited-slip differential also minimizes wheel-spin on the inner wheel during hard cornering for smooth, predictable power delivery. Mazda also fits a similar Super-LSD unit to the rotary-powered RX-8 sports car and the high-performance MAZDASPEED6 sports sedan."

To test it on a lift, I would have someone hold one wheel stationary, then someone else rotate the other wheel in the forward direction. If all is working properly the wheel rotated will develop quite a bit of resistance to rotation, depending on the LSD slip settings.

Here is what we have in the Speed3/6 http://www.gkndriveline.com/drivelin...super-lsd.html

I assume the "similar" diffs have differing amounts of slip torque as the Speed3 FWD MUST allow some free-turning wheel speed difference for the car to turn reliably at slow speeds on slippery surfaces(required for mass-market liability concerns). If you guys popped for a racing/clutch type front diff, you would have MUCH LESS torque steer.

I ran the Mazdaspeed Motorsports multi-clutch 2-way (60% lock) version in my FWD autocross car.....

[Silver Ecstasy]

Nice, ok thanks!!

[R.MS3]

Well Silver, I'm pretty sure you know i'm having the same problems as you do. High LTFT's and hesitations, along with some PT knock.

I'm pretty sure that at this point, it's a tune issue. Combining very cold weather (which we're both facing right now) and a stock tune, is sending the trims way up there to compensate for the extra cold air. My car is feeling like shit right now and i'm driving like a granny. At this point i'm starting to look at buying an AP and tune the bitch out. I went through 2 different TIP's, put the stock BPV back in, replaced the purge valve solenoid and nothing.

Question for the pros: When i uninstalled my intake a couple of weeks ago, the "arm" that goes from the valve cover into the intake (right after the MAF, at the curve), had a little bit of fluid in it, i think oil. I'm pretty sure that's not normal? I checked the connection at the valve colver and you can easily move the arm back and forth at that connection but it wasn't loose. Just looks like it was designed that way.

That got me worried a bit so i'm wondering what can it be?

[Silver Ecstasy]

Well, the knock I wouldn't be concerned with honestly. I've gotten several confirmations from techs and engineers that the KR counts are simply emissions changes the car is making, trying to squeeze out the best possible gas mileage. Unless you hear a knock, it's nothing to worry about.

I'm pretty positive that oil is normal. Hence, why a lot of people like to block that line out, or put a catch can on. The idea of that oil re-entering the engine horrifies everyone. I for one, could careless. The car's going to do what it wants to do regardless. I'm tired of worrying about it.

Once they replace my MAF today, I will be re-installing my Cobb SRI, and finally installing the TIP in conjuction with it. We shall definitely see how things go.

My LTFT's are literally perfect with the stock airbox in. Unreal how quickly they go to normal with the safety box on (that's what i'm calling it from now on lol).

[Silver Ecstasy]

New MAF, weird that the volts are pretty much the same (I don't know how they diagnosed it as bad). Either way, the erratic hesitation is still there. Feels like the BPV just opens and closes so quickly during part throttle, that it causes the hesitation. You could hear it with the SRI on because the bpv would bleed when the hesitation was happening.

Almost starting to make me feel like the BPV is defective somehow?

[IndianOutlaw]

I hope you get everything solved soon..
I also have the cobb sri (and turbosmart hybrid) and my LTFT's have been +13 at wot.
I replaced the turbosmart with a hks ssqv in full recirc and now they seem to be at +18.

So i think we're in the same boat, hopefully we can get it fixed soon without spending much since buying an AP is out of the question now.

[Silver Ecstasy]

Man, how bizzare! Why such nasty LTFT's?? And the car would not "Learn around it". I PM'd Cobb. Their answer? Buy an AP. Unreal..

[FORZDA 1]

Originally Posted by IndianOutlaw I hope you get everything solved soon.. I also have the cobb sri (and turbosmart hybrid) and my LTFT's have been +13 at wot. I replaced the turbosmart with a hks ssqv in full recirc and now they seem to be at +18. So i think we're in the same boat, hopefully we can get it fixed soon without spending much since buying an AP is out of the question now.

If your LTFT is reading anything other than 0.016 at WOT, then you are not in open loop. You are still in closed loop and the ECU is still running the CL fuel table. You MUST be in Open Loop at WOT to ensure safe AFRs. I can't deduce why you're still in Closed Loop at WOT unless you're not holding it there long enough for the ECU to transition. There are delays set in the ECU.

Oh, and buying an AP with a tune WILL fix it.....

Originally Posted by Silver Ecstasy New MAF, weird that the volts are pretty much the same (I don't know how they diagnosed it as bad). .....

Doood, they didn't diagnose anything, they shotgunned parts at it like ALL(well practically) stealership goons.

Almost starting to make me feel like the BPV is defective somehow?

Well, it isn't impossible. You REALLY need a competent tech to look drive your car and diagnose the issue. I suppose you can keep taking it back to your dealer and let them replace a few more parts and then tell you "they all do that" to try and get rid of you....

[matsuda]

Originally Posted by Silver Ecstasy Yeah for sure. I can't imagine why the O2 sensor would be bad either, unless the raw fuel I wasn't burning fouled the plug up a little bit (when I cleaned my MSCAI and it was hesitating FOR REAL, not like this kind of hesitation where it's so subtle yet you feel the car slowing. That time, the car was bucking hardcore). Either way, we're slowly but surely working on it. And my Cobb SRI and TIP will be going on the car real soon. I'm not digging the stock airbox ROFL. Yeah we will definitely see! I can only hope. I'm also considering installing Denso ITV22's in the car to see if that fixes anything. Otherwise, i'm stuck with this being a mechanical issue (floating brake caliper that keeps engaging? I had a rock get stuck in it back in October). When the car's on the lift, how do you test the Limited Slip Diff? Arn't the wheels supposed to rotate opposite of one another when the car is in neutral?

Why in the world would you consider intalling COLDER plugs (i.e. plugs that are more likely to foul) to fix a hesitation issue?

Regarding the LSD, keep in mind that it is a torque sensing type. The only practical way to test it is to "lay down some rubber" (cringe).

Originally Posted by Silver Ecstasy New MAF, weird that the volts are pretty much the same (I don't know how they diagnosed it as bad). Either way, the erratic hesitation is still there. Feels like the BPV just opens and closes so quickly during part throttle, that it causes the hesitation. You could hear it with the SRI on because the bpv would bleed when the hesitation was happening. Almost starting to make me feel like the BPV is defective somehow?

Considering that the LTFT was zero at idle (with the stock airbox), it would be highly unlikely that the MAF is bad. The people that were working on your car should have realized this.

Originally Posted by FORZDA 1 If your LTFT is reading anything other than 0.016 at WOT, then you are not in open loop.

That is not true in the case of a MS3 with no AP.

Originally Posted by ReNaToMS3 Well Silver, I'm pretty sure you know i'm having the same problems as you do. High LTFT's and hesitations, along with some PT knock. I'm pretty sure that at this point, it's a tune issue. Combining very cold weather (which we're both facing right now) and a stock tune, is sending the trims way up there to compensate for the extra cold air. My car is feeling like shit right now and i'm driving like a granny. At this point i'm starting to look at buying an AP and tune the bitch out. I went through 2 different TIP's, put the stock BPV back in, replaced the purge valve solenoid and nothing.

Don't try to "fix" a real problem by "tuning it out". The MAF sensor (which measures air mass) will meter cold air correctly. In other words, fuel trims should not increase in colder weather.

[R.MS3]

Yeah i pretty much realized that i'm getting +19% LTFT is because of the cold weather and no tune.

If it was in warmer weather, it would probably be around 10-12%.

So i stopped worrying about it for now and thinking about a tune.

My local tuner that uses the TunerPro from Cobb is asking for a $400-$500 tune because mazdaspeeds takes a bit longer to tune than most cars. Is that too much?

He also said most of the speeds he tuned had crazy maf tables and too much timing correction with the stock tune.

[Silver Ecstasy]

Fuel Trims HAVE typically increased dramatically with SRI's. The increased amount of air is likely to confuse the ECU into thinking it's going to need to compensate with lots more fuel as well.

Colder plugs? They should make the car run smoother, atleast from what I've heard. I don't see what the issue is?

I'm going to ignore it until I re-install the SRI in warmer temps.

[felt]

I wouldn't put colder plugs in unless you're running some sort of tune besides stock..

[R.MS3]

Yeah Siver, you should only have when you install bigger mods like a DP, FMIC/TMIC, bigger turbo, or if you tune it. They will just foul quicker. The only thing you will probably benefit it from is a bit less KR but it's not even sure.

I would say don't waste the money.

[FORZDA 1]

Originally Posted by matsuda ........That is not true in the case of a MS3 with no AP......

I'm not sure why you think this. The open loop value LTFT has nothing to do with the AP and EVERYTHING to do with the ECU being in open loop. The ECU does NOT apply LTFT while in open loop. This is why you get the weird transitional problems and blubbering when running a piggyback type tune which can ONLY affect open loop via the MAF input. The AP CAN affect the closed loop AFR targets and the transition delay if you change them in those tables, but I'll state it one more time for clarity,

THE ECU DOES NOT OUTPUT A LTFT IN OPEN LOOP.

It runs the open loop AFR tables. Not trying to be difficult, just trying to make sure the folks know what they're looking at.

[matsuda]

Originally Posted by FORZDA 1 I'm not sure why you think this. The open loop value LTFT has nothing to do with the AP and EVERYTHING to do with the ECU being in open loop. The ECU does NOT apply LTFT while in open loop. This is why you get the weird transitional problems and blubbering when running a piggyback type tune which can ONLY affect open loop via the MAF input. The AP CAN affect the closed loop AFR targets and the transition delay if you change them in those tables, but I'll state it one more time for clarity, THE ECU DOES NOT OUTPUT A LTFT IN OPEN LOOP. It runs the open loop AFR tables. Not trying to be difficult, just trying to make sure the folks know what they're looking at.

No...

When monitoring open/closed loop and LTFT, the LTFT does NOT zero out at WOT and open loop (i.e. the LTFT reading is constant at WOT in open or closed loop operation).

Mind you I am talking about a MS3 with no AP. I don't own an AP but I believe that it does zero out the LTFT at WOT/open loop.

[matsuda]

Originally Posted by Silver Ecstasy Fuel Trims HAVE typically increased dramatically with SRI's. The increased amount of air is likely to confuse the ECU into thinking it's going to need to compensate with lots more fuel as well.

The ECU wouldn't be confused. More (metered) air simply equals more fuel added. If the air is metered properly, the fuel trims shouldn't change. For example, a good intake such as the CP-E CAI typically has negative fuel trims.

[FORZDA 1]

Originally Posted by matsuda No... When monitoring open/closed loop and LTFT, the LTFT does NOT zero out at WOT and open loop (i.e. the LTFT reading is constant at WOT in open or closed loop operation). Mind you I am talking about a MS3 with no AP. I don't own an AP but I believe that it does zero out the LTFT at WOT/open loop.

Ok, how do you know you're in open loop? I recommend you go out and run a DH log at WOT. Make sure to include Abs Throt and LTFT. You MUST hold WOT for several seconds if you're running OEM tune before the delays are met and the ECU will transition into open loop. You likely won't even go open loop in first or second gear because the transition delays don't time out. Try it in 3rd or 4th so you can hold it WOT for several seconds and post up the log.

The zeroing of LTFT is your only sure indication that the ECU is actually in open loop.... Just try it like I said and post it up to prove me wrong.

[easy]

y not try a different bpv ...

u said the first few days were good and u spiked and held better than when you were on the cai, so maybe your stock bpv just gave out or is leaking. Time to upgrade!

[matsuda]

Originally Posted by FORZDA 1 Ok, how do you know you're in open loop? I recommend you go out and run a DH log at WOT. Make sure to include Abs Throt and LTFT. You MUST hold WOT for several seconds if you're running OEM tune before the delays are met and the ECU will transition into open loop. You likely won't even go open loop in first or second gear because the transition delays don't time out. Try it in 3rd or 4th so you can hold it WOT for several seconds and post up the log. The zeroing of LTFT is your only sure indication that the ECU is actually in open loop.... Just try it like I said and post it up to prove me wrong.

How do I know? I monitor fuel system status (as defined in the SAE J1979 (OBD2)specification). According to the spec, there are 5 possible conditions:

1. Open loop - has not yet satisfied conditions to go closed loop

2. Closed loop - using oxygen sensor(s) as feedback for fuel control

3. Open loop due to driving conditions (e.g., power enrichment, deceleration enleanment)

4. Open loop - due to detected system fault

5. Closed loop, but fault with at least one oxygen sensor - may be using single oxygen sensor for fuel control

I have an IDS system. I'm not sure if a DH can monitor this, but I am assuming that it can.

You are right in that WOT doesn't necessarily = open loop. Open loop typically occurs only at high loads and high RPM's.

[FORZDA 1]

Originally Posted by matsuda ........If the air is metered properly, the fuel trims shouldn't change. For example, a good intake such as the CP-E CAI typically has negative fuel trims.

Dude, maybe I'm misunderstanding what you're trying to say, but I get the impression that you REALLY must spend some time reading up on the details of ECU operation and follow it up with some testing on your car to prove it to yourself.

The fuel trims WILL change if the intake size parameters (size, length, MAF position, etc.) are not EXACTLY the same as the OEM calibration("metering"). The changes may be small or LARGE, depending on what has changed.

CPE claims to have spent quite some time on their CAI to position the MAF in a location that would not change the "metered" air mass and adversely affect the fuel trims. Apparently succeded with the slightly negative trims meaning the MAF value is a bit higher than the target and the ECU is pulling a bit of fuel. Other CAI brands like MSCAI position the MAF in a location that results in positive fuel trims meaning the MAF value is a bit low and the ECU is adding more fuel.

The MAF (re)positioning can be used to mechanically affect the open loop AFRs via the MAF sensed "metering" changes. The closed loop trims will be "off" somewhat but they aren't used in open loop so the WOT open loop AFR can be "tuned" mechanically.

[tunersteve]

I've been trying to help Mike with this issue, and since we live close, I still have yet to drive the car and see if I can pick up what he's talking about. Honestly, I think it's weather related, and it's something that warm weather didn't allow to happen.

I don't think it's the BPV, although its opening & closing according to him, at what boost levels and throttle position, it's hard to deduce.

I did think it was the CDFP at one point, but I'm not sure. I told him to DH log it and post it up for us to look at or send it to me, but I haven't got that yet.

The MAF is a 1-5VDC signal, in which anything outside of that will throw the CEL for high/low MAF voltage (like water getting on the MAF).

I'm hoping that we can pinpoint this and I'm hoping to get some time behind the wheel of his car and see if we can duplicate the issues and report back.

[FORZDA 1]

Originally Posted by tunersteve .......I'm hoping that we can pinpoint this and I'm hoping to get some time behind the wheel of his car and see if we can duplicate the issues and report back.

Thanks Steve!

Oh, just popped into my head... log and sanity check the IAT readings. If the IAT is "off", the MAF temp bias will be incorrect and obviously all the fuel trims and closed loop AFRs will be skewed. The MAF has been replaced so it could be a connector issue at the MAF or ECU.

[fjames]

Too hard to root through and quote stuff, so I'll just say my piece and you guys figure it out On the LTFT/OL/WOT thing - you guys are missing the rpm variable. My view ... WOT+OL+<5K=LTFTs are dropped. The CL map only goes to 5K as supporting evidence.

On the intake vs. fuel trim thing - I don't see how you can
a. let in more air consistently over time
b. say that because of this your ecu increases fuel
c. claim no fuel trim change
d. because that IS a fuel trim change.

If your ecu is adding fuel consistently over time, it will write it to "long term memory" and that's your LTFT.

Comparing a CAI to SRI is meaningless in this discussion as CAIs generally don't reduce restriction over the stock intake. If I added an intake and saw it resulted in a negative movement in LTFT I'd be pissed lol.

[FORZDA 1]

Originally Posted by fjames Too hard to root through and quote stuff, so I'll just say my piece and you guys figure it out On the LTFT/OL/WOT thing - you guys are missing the rpm variable. My view ... WOT+OL+<5K=LTFTs are dropped. The CL map only goes to 5K as supporting evidence.

Thanks fj, but I'm not missing anything in the equation, unlike ol' matsuda. The 5k rpm max in the table values is a hard switchpoint, BUT the ECU will still run the last closed loop value until the delay times out. The main point for readers to take away from this side-discussion is that the LTFT will be essentially ZERO in open loop.

On the intake vs. fuel trim thing - I don't see how you can a. let in more air consistently over time b. say that because of this your ecu increases fuel c. claim no fuel trim change d. because that IS a fuel trim change. If your ecu is adding fuel consistently over time, it will write it to "long term memory" and that's your LTFT. Comparing a CAI to SRI is meaningless in this discussion as CAIs generally don't reduce restriction over the stock intake. If I added an intake and saw it resulted in a negative movement in LTFT I'd be pissed lol.

Yeah, it all got distracted by matsuda's incorrect inputs. Back to the real issue for the OP.

[FORZDA 1]

Originally Posted by matsuda How do I know? I monitor fuel system status (as defined in the SAE J1979 (OBD2)specification). According to the spec, there are 5 possible conditions: 1. Open loop - has not yet satisfied conditions to go closed loop 2. Closed loop - using oxygen sensor(s) as feedback for fuel control 3. Open loop due to driving conditions (e.g., power enrichment, deceleration enleanment) 4. Open loop - due to detected system fault 5. Closed loop, but fault with at least one oxygen sensor - may be using single oxygen sensor for fuel control I have an IDS system. I'm not sure if a DH can monitor this, but I am assuming that it can. You are right in that WOT doesn't necessarily = open loop. Open loop typically occurs only at high loads and high RPM's.

Dude, I've been trying to be courteous and push you towards learning a bit about the specific open/closed loop switching logic in the Speed3/6 ECU, but it's plain to me you're simply a troll who has read some basic theory in the SAE documents that define the basic PID standards that the OEMs must follow in setting up their OBD communications for viewing by scanners, etc. It has nothing to do with the actual ECU function. Quoting basic PID info from the SAE standard just proves how little you actually know. It may impress some folks who have no clue what's going on here, but from my perspective please just go away if you're not going to learn anything because you obviously have no real knowledge about the information you're posting and crapping up this and the other threads you've posted in.

[fjames]

Originally Posted by FORZDA 1 Thanks fj, but I'm not missing anything in the equation, unlike ol' matsuda. The 5k rpm max in the table values is a hard switchpoint, BUT the ECU will still run the last closed loop value until the delay times out. The main point for readers to take away from this side-discussion is that the LTFT will be essentially ZERO in open loop. Yeah, it all got distracted by matsuda's incorrect inputs. Back to the real issue for the OP.

Just to clarify, my intent was to show a scenario where it was essentially impossible not to see LTFT drop out.

On the topic at hand, part of it is solved - SRI+no tune+Michigan winter =issues.

The hesitation is beyond me, but rereading the thread makes me wonder about that plastic piece that came off. Secret damage to some wire or hose possibly? Has Silver actually pulled the plugs for inspection? Is there absolutely no issue on acceleration, it's all deceleration? Does it do it after driving for more than 45 minutes?

[FORZDA 1]

Originally Posted by fjames Just to clarify, my intent was to show a scenario where it was essentially impossible not to see LTFT drop out.

Got it! Thanks!

On the topic at hand, part of it is solved - SRI+no tune+Michigan winter =issues. The hesitation is beyond me, but rereading the thread makes me wonder about that plastic piece that came off. Secret damage to some wire or hose possibly? Has Silver actually pulled the plugs for inspection? Is there absolutely no issue on acceleration, it's all deceleration? Does it do it after driving for more than 45 minutes?

Yep, hopefully tunersteve will get a chance for some firsthand observations and find the root cause issue.

[tunersteve]

The only somewhat relevant issue I had with my car when untuned was last year during the winter I would get a fuel/boost cut under cold temps with my MSCAI and Cobb TIP. I suspect it was merely temp related, and never came up when the weather warmed up.

[R.MS3]

I think the problem here is the COBB SRI. Somehow it just shoots your LTFT's way higher than it's supposed to under cold weather, with no tune.

I think Silver stated that with the MSCAI he was seeing higher LTFT's but not in the 15-20% range he is seeing with the COBB.

I also think part of the hesitation problem is the knock retard sensor trying to put more fuel into the mixture/pulling timing because it's seeing too much cold air coming in, trying to prevent knock? I don't know.

That's at least what i'm seeing with my car right now. After it's warmed up, you nanny the car and you don't see any KR. As soon as you step on the throttle a little more, usually in higher gear but not going WOT, KR comes in right away, ranging from as little as 1 to 5 degrees and then i don't see it again unless i step on it again 10 miles later.

[Silver Ecstasy]

Ok, let me completely clarify everything so we can start fresh:

MSCAI was installed last January. After grabbing a Dashhawk, I started to realize that I wasn't hitting Boost targets like i'd expect. 15psi was hardly ever a reality. I had tried a Forge BPV and TS BPV and neither corrected the issue. Infact, it made the car feel like more of a dog. The plastic piece was something that had to be removed to install the MSCAI. I was there with the tech when he re-installed the piece, no problem.

I un-installed the MSCAI for the Cobb SRI and instantly started hitting 15+ all the time, in any gear, and the car seriously pulled like a raped ape. I was shocked at what a difference it made and it got really addictive. I couldn't stop myself from trying to rip the tires apart lol.

I then ended up taking it to the dealer so they could replace that splash shield (We figured out that it actually directs air up to the HID ballast which sits underneath the driver's headlight). They also noticed an oil pan leak and re-sealed the pan under warranty.

Ever since that point, the car will slightly hesitate. I've tried several ways to diagnose or document what it's doing (outside of doing straight logging). No strange KR counts during these phenomenon, no change in RPMs or engine speed, just that gut feeling the car is actually slowing down. As if someone was pressing the brakes lightly while having the gas pedal down. This is happening both after I had the pan re-sealed (and the Cobb SRI was installed) right down the past 2 weeks i've been running the stock air box.

The only reason I brought up the BPV is because at super light throttle, the bpv will do this open/close flutter when the throttle input is enough to build some boost, but not enough to keep the bpv shut, so it will release any pressure and you'll feel that lack of acceleration (at light throttle and low speeds - think traffic and holding a gear, and exercising the revs because of stop and go traffic). I always thought it was weird if I had the hold the gear to accelerate only to have to slow down, and the engine would sorta snap once (even with an aftermarket MM) and you'd DEFINITELY feel that hesitation/snap if you had to abruptly reduce throttle position, but that's a typical characteristic of manual trans.

For the sake of info (this has nothing to do with my issue, but was a part of the original convo that the SRI's cause some WEIRD LTFT's)

MSCAI Fuel Trims
-Idle 5.5
-WOT 3.1
-Cruise 2.3

Cobb SRI Fuel Trims
-Idle 15.6
-WOT 8.4
-Cruise 16

Stock Airbox Fuel Trims
-Idle -3.1
-WOT 0.0
Cruise 0.8

I just don't what else to look for really. The oil pan fix has NOTHING to do with the engine hesitating. You'd almost imagine it's a vacuum leak issue somewhere maybe, or a grounding out somewhere?

Steve has been a big help and i'm hoping he can check it out eventually to help verify it. Dealership doesn't think anything is wrong, but they don't own the car, they don't know what even to look for. I even went for a ride and drove and showed him what the car would do (upon decel specifically) where it would hiccup as you'd let off the throttle and the car would decelerate.

[easy]

u mentioned on the other forums that u had flucuations in vaccum when monitoring on dh. Possible a vaccum leak u can't see or hear? May do a vaccum leak test

[tunersteve]

I'm really not concerned with anything prior to the SRI install. I will be bringing my stock BPV to test on the car, since I have never had an issue with mine (although I've swapped for the SU/TS BPV)(FORZDA, you can't have mine! LOL). I may also throw my AP on his car and see what it does. We've got a lot of options and I hope to take a systematic approach to ruling things out.

I think the BPV is not the issue, and I say that because Mike seems to notice more BPV fluctuations than anyone I've ever met (no offense Mike!). What he may be seeing might be normal for any DISI MZR motor.

I'll put some sort of plan of attack together tonight or tomorrow, and I'm open to suggestions.