Wideband & EGT combo probe?
 

Does anyone know of a combination wideband and EGT probe? I have one extra bung on my DP that I'd like to use for both. I'm suspicious that the extra two wires on the upper factory O2 are for an EGT probe. I know you can mount the thermocouple to the outside of the exhaust pipe, but I would like to have the reaction speed of an in-stream sensor.

Typically/ideally you will want the EGT probe pre-turbo, while the WB post turbo... having the EGT post turbo wont really give you a whole lot of useful info, other than to compare temps before/after you try a different tune or whatever...but the absolute value really won't mean much.

Haven't heard of any - a lot of it has to do that the WBO2 is heated artificially and maintained at a particular temperature which would skew the thermocouple's readings.

Ah, yah, duh and duh. Turbo is gonna pull a lot of energy out of the exhaust stream and skew the readings. So can I just tap a runner on my header or do you usually use a bung for an EGT probe?

yes bung

bunghole?

I drilled and tapped a hole in cylinder 3 runner on mine....cast stock mani is thick enough. OR you can put it around the collector, right before it goes into the turbo, and sort of get an average EGT temp- that might be the best idea. Cyl 3 is usually the hottest which is why I did it, but it's sorta an ass pain to get to, I might have done the collector area if I could do it again.

It really depends on how you're gonna use the EGT. If you no shit want to know cylinder temps, and are tuning off of EGT...then pre turbo no brainer. But if you are just more interested in seeing before/after lets say you add...meth, new spark plugs, 19 vs 21psi etc...or maybe just a rice factor (lol), then sure go post turbo, and get a bung welded on, a lot easier install.

For general EGT monitoring I would use it after the turbo.
For tuning off of EGT I would go pre turbo.

The problem with running a EGT probe pre turbo on a daily driver is that the probe can break off from the 400+mph air speed and 1700+* temps and then it will go through the turbine wheel and grenade the turbo. It doesnt happen very often, but if it does it will really suck.

I know on my Defi EGT the probe is actually bent some, so I know it has partially melted at least once. I am running it after the turbo.

There arent any EGT/WB combo sensors out there. The extra wires on the 4 and 5 wire widebands are for a heating element and ground.