Help o2 Sensors Fucked?

[breakfstincluded]

This is a log at startup after a very rough one and still rough idle.

Also re-flashed to reset fuel trims.

There is no knock.

Lights shudder a little when I rev slightly.

I suspect o2 sensors because my STFT seems stuck at 24.8.

Start up is rough, stabilizes but exhaust sounds strange and is slow with fluctuations while getting back to idle rpm after any throttle.

I've never kept logs at start up before and wanted to make sure this isn't some common phenomenon of a recently flashed car.

[breakfstincluded]

even a massive boost leak would have fluctuations with good o2 sensors right?

[triplejumper18]

If it's O2 sensors, I have spare ones.

[breakfstincluded]

you're my hero

[p057]

anyone local you can just swap with to test?

After DP, it isnt hard to get to and try out. Hope for the best.

[smoogs12]

No codes?

edit: That log definitely looks like a bad o2.

edit2: or a vacuum leak.

[breakfstincluded]

code probably would show up if i drove it for a bit.

so I'm pretty sure these are the causes.

1. My own dumbass.

2. Running out of ideas to fix LTFT issues since DP install and suspecting I got copper anti-seize on the threads.

3. Attempting to clean o2 sensors with this.



So lesson learned, dont' try to clean your o2 sensors, maybe maf cleaner would've been a better bet, but googling anyplace else, it sounds like if its dirty, its not gonna get better.

triplejumper18 hooked me up with spare o2 sensors from his MS6 for 200 (:

[smoogs12]

Your trims could go rich like that if you have a vac leak.

Hows you idle? is it smooth or rough? your op leads me to believe that its smooth, but I felt like it was worth asking.

Because if your o2 sensor was toast your car would go into ol fueling so you wold have no trims.

[breakfstincluded]

hmmm idle looks smoothe if im looking at my tach, the exhaust tells me different though.

I just leak tested and its pretty sealed and quiet. At maf and at throttle body.

I also just changed to NGK iridiums and gapped them to 28

My only other problem lately is my purge valve solenoid.

I've gone through maybe 4 in the last year, 2 in the last 2 months.

when i replace it, fuel trims will look normal, but the sypmtoims will return and my LTFT will go -10 or -15 at the most. These have been replacements from rockauto.

I'm trying an OEM replacement next.

They've never leaked however, ill suck and blow on both ends and its sealed.
I'll replace when I get the strange fuel trims and I get CEL P0441.

Its definitly not clogged on the hose side that goes to the intake manifold either.

The toher hose that goes back towards the cabin, im not sure how to check, if I suck I can hear what almost sounds like bubbling.

[smoogs12]

Ok so this is me just kind of thinking out loud so to speak, but the thing with your purge valve makes sense.

Valve is toast so the egr just keeps shitting into the intake mani and dilutes the air fuel mixture and causes low vac readings.

We are talking about your vac switching valve/solenoid right?

[breakfstincluded]

this one would be correct

I kinda hope the problem couldn't possibly be JUST my PVS though because I just bought a set of o2 sensors for 200 bucks haha

[smoogs12]

If it is just the solenoid I'm sure you could sell the o2 sensors no problem. People are always roasting those things.

Tapa

[breakfstincluded]

I'll find out when I replace my o2 sensors today and see if the STFT is stuck at 24.8 still.

I've read suggestions on lubing the PVS, so I'm trying that too.

Damn oem replacement hasn't shipped yet and is coming from north carolina

[btstarcher]

When my primary o2 sensor took a shit my AFR's were stuck at 29. I guess they could fail differently, but your AFR's are changing. I'm leaning toward a dirty sensor or something else. Notice your LTFT are in OL (.16). Only the STFT are changing.

[breakfstincluded]

Yeah I've been contemplating the idea that only one of the sensors is screwed, but im not sure that would be easy to test, unless i installed various combinations of the now 4 sensors i have, and see which one shows me the prettiest numbers at idle

[mrQQ]

how about an exhaust leak?

[breakfstincluded]

I tried that, I don't hear anything that could be leak, and there's no black soot anywhere, theres copper gakset thats as orange as the day i used it on there hehe.

This change in STFT comes after changing spark plugs from ITV22 to NGK equivilants, attempting to clean o2 sensors with crc electronic parts cleaner, and attempting to lube PVS.

[smoogs12]

I really think that the solenoid will fix this.

Did you get the o2 sensors yet? The way you worded your post made it kinda sound like you did.

Tapa

[breakfstincluded]

Yeah i got a set from triplejumper18, I'll put them in later today.

the new OEM PVS solenoid won't arrive til later this coming week

[smoogs12]

breakfstincluded any update?

[breakfstincluded]

Yeah I got the OEM mazda PVS in, so i hooope it works...

I started the car though and STFT was stuck at 25.

Then i proceeded to change o2 sensors from the ones i got from triplejumper....

Note to self, MS3 and MS6 have reversed plugs from eachother lol

sucks, I'm gonna get a set from edge, and should be here when i get back from seein the gf for a week

After that I'll know for sure if the OEM PVS works... would be nice because I've now bought 3 from rockauto (Dorman brand) and 1 from onlinemazdaparts...

I would hate to find out I need a new charcoal cansiter or some shit no one ever has issues with.

[smoogs12]

Damn, so the new solenoid didnt fix it?

[breakfstincluded]

ah no, but i wouldn't guess it would.

The symptoms of a bad PVS are different in my experience.

The LTFT jumps up and down up to about 15, and I might be able to correlate it with acceleration and cruise/idle... acceleration being when it's closest to normal.

Sometimes not even in WOT, it appears to go open loop and my LTFT will be 0 just on the freeway.

[btstarcher]

This may be a stupid question, but are you disconnecting the battery when you replace the sensor? And if so, are you driving awhile so that the ecu "learns" the fuel trims? I don't even know if it matters, but when I flashed a new map, my LTFT always started out .16 and my STFT jumped around a bit.

[breakfstincluded]

Right, yeah I'm aware of that, sometimes I'll reset it on purpose if I'm cleaning my maf or boost leak testing or things like that.

I've only seen my fuel trims at idle for this issue, since I'd rather not drive around with basically no o2 sensors. What I'm seeing isn't typical of fuel trims at idle.

[btstarcher]

You really need to drive it to make sure. It won't hurt anything. Just don't go WOT.

[breakfstincluded]

I'm pretty sure it's an indication of fouled sensor if it's stuck at 25 at idle, I've also given it gas to about 3 grand and it's mostly the same thing.

If it was normal otherwise I miiiight consider it. But the exhaust also sound sporadic at times

Do you think the o2's need to be driven on to be warmed up to function again since cleaning or something?

[btstarcher]

It also could be a boost leak. All it means is that the ecu thinks your car is running lean. What I want to see is whether or not the LTFT goes to some crazy high number, and what your AFR looks like. The fact that your AFR was changing in the log is what confuses me; like I said, when my O2 sensor failed, AFR was stuck at 29.

[smoogs12]

In most cases that I've seen, the afr will stick at 14.7 when the primary o2 has failed.

Also confused why you haven't thrown a code if the cause of all this was a bad o2

Tapa

[btstarcher]

Originally Posted by smoogs12 In most cases that I've seen, the afr will stick at 14.7 when the primary o2 has failed. Also confused why you haven't thrown a code if the cause of all this was a bad o2 Tapa

When my primary failed it was stuck at 29.29; I thought that when they fail, the ecu would want to command more fuel to prevent the possibility of running lean?

[breakfstincluded]

I'm guessing like things like EGR or PVS, it takes a few cycles or miles to throw cel.

I thinkt he only immediate cels I've ever received are from unplugging electrical connections.

Also, it might help to say that although the log above is from AP.

I've been watching real time on my Dashhawk since that one to see if any changes, some extreme numbers show up differently on it.

Like I believe idle vacuum will show up differently on DH than on AP with a more extreme negative number on DH.

[smoogs12]

Originally Posted by breakfstincluded I'm guessing like things like EGR or PVS, it takes a few cycles or miles to throw cel. I thinkt he only immediate cels I've ever received are from unplugging electrical connections. Also, it might help to say that although the log above is from AP. I've been watching real time on my Dashhawk since that one to see if any changes, some extreme numbers show up differently on it. Like I believe idle vacuum will show up differently on DH than on AP with a more extreme negative number on DH.

That's because the dh reads vac in inhg and the ap reads psi.

Originally Posted by btstarcher When my primary failed it was stuck at 29.29; I thought that when they fail, the ecu would want to command more fuel to prevent the possibility of running lean?

If your o2 has failed you'll be in open loop fueling. So all input from your o2 sensor is ignored anyways.

Tapa

[breakfstincluded]

The ap reads vacuum in psi?

Because I have an extra slot (6 pararmenters) I have vaacum and boost, so actually when I'm in boost, vacuum and boost parameters will read the same, which is in PSI.

In vacuum, boost is always at zero, and vacuum will read in hg like you described.

But aren't there these other people getting stuck numbers that are indicating fouled sensors opposed to just 0% or even -.16? They seem to be citing 30, 24, and 26 and similar high numbers.

[smoogs12]

Pretty sure the most that the trims can add or subtract is 25%.

Anything past that and you'd throw a lean/rich code.

But with a failed o2 like I said, you should go into ol fueling, which as I'm sure you know would result in trim values of .16

Tapa

[breakfstincluded]

So you think that it's possible that for those of us who have stuck fuel trims at like 25 or so, might not have fouled sensors and just need to drive on it a little?

[btstarcher]

Fuck if I know....all I know is that it's worth investigating.

[breakfstincluded]

When my turbo was smoking, I would inadverdently reset my fuel trims while investigating, and then leave my car to idle for 15 minutes, 40 minutes at most.

Fuel trims definitely don't look stuck during this time, they're constantly adjusting.

The only possibility I could consider is after cleaning my oxygen sensors... if they need to be blasted with exhaust before working properly.

In which case my fuel trims will look the same stuck at 25 when I get the new o2 sensors in later this week.

fuck o2 sensors, I'm catless, i should just run with 1 sensor.

[btstarcher]

Why are you looking at fuel trims and not afr? Just a question; I always thought that since the O2 sensor measured afr then that would be the parameter to look at.

[smoogs12]

You might have said this already, but have you checked for vac leaks?

Like legitimately checked with either carb cleaner or (if you have the means to) a smoke test?

Tapa

[breakfstincluded]

lol i'm probably too paranoid about leak testing.

I've boost leak tested at the throttle body, put the intercooler back on with charge tubes and tested at the turbo, tested at the intake without recirc and breather hose.

and with recirc and breather hose at a much lower psi.

I'll make sure it all holds at wastegate pressure or a bit higher if im daring, anymore at the intake and the MAF housing will probably leak at it's o-ring since its not designed for that, or things might leak on the valve cover if you leak test witht he breather on.

Also it's held before and after i cleaned my o2 sensors.