I'm getting ready to install a flex up-pipe and I would like to know what to do with the stock EGT probe.. DO I use a cel fix for the up-pipe and rear EGT, if so is it the same Resistor? I have a Defi EGT probe that I was going to tap into my header, is this the right way to go about it?
thanks

 

First about CEL fixes and probes:

The uppipe = EGT Sensor. Only used to make sure the Uppipe cat is not on fire. If cat is gone, the OEM EGT probe will fail (some may argue...but better safe than sorry). You need to remove it, plug the hole with a bolt (M12x1.25) and get a 2.2k ohm (2,200 ohm) 1/2 watt resistor as referenced in this thread.

You don't want to leave the sensor in and let it fail, at best it triggers a CEL, at worst it trips limp mode which makes it impossible to rev over 3k and you basically limp home, or at WORST it breaks up and goes through your turbo (probably more lore than actually happening).

The midpipe = Rear 02 Sensor. This only monitors the efficiency of the cats. You "might" not get a CEL with only removing the uppipe cat, but any other cat removal will trigger a CEL (P0420). A fix like the Pony Express MIL eliminator should take care of you (it's not a resistor it's some kind of simple voltage clamping circuit). Mine has worked for 20k miles.

Now about tapping for the EGT gauge. Tapping the manifold is DEFINITELY the right way to do it. Most people tap just outside cylinder 3 or 4...there is a flat casting spot on the manifold that is perfect for the tap. Putting an aftermarket probe in the uppipe is a waste of time...the temps are way lower than what the actual exhaust gases are (what you care about for tuning/monitoring).

 

Great, thanks for the insight, in record time too!

 

Hahaha...doing my nightly "earn the ScoobySnacks". Good luck.

+3