22.4 AFR @ Idle
 

I recently got my TSE turbo kit (EFR 6258) running (MS3 Basic from TSE). After starting and revving it for ~30 seconds, it settles into a low (500 RPM) idle and the AFR (Innovate MTX-L) gauge reads 22.4. I have taken it out for a few drives and under load the AFR reads expected numbers (14.7 at cruise, 13s up slight grades, 8-10 at WOT).

Has anyone else experienced this with this gauge? By the way, it ran for 1 year NA with this gauge and it always behaved (14.7 at idle). I'm thinking the gauge is shot. I did try installing a new O2 sensor with no effect.

Thanks!

Fix the leak. And then tune the car.

Not sure what your experience is with tuning the MS3, but based on the "it's not getting enough fuel at idle"... Did you try adding fuel to the idle cells of your fuel map?

@18psi: I thought I had an intake leak that I took care of. I will look again.

@pdexta: I have little experience tuning the MS3 (I guess it shows!) but I never said "it's not getting enough fuel at idle". My thought is the gauge is acting up, although I am concerned it could be too lean, since the gauge is telling me so. Per your advice, I'll take a look at the fuel map.

Thanks!

I believe 18psi is referring to an exhaust leak. Typically there's an exhaust leak by the wideband it'll show at idle but read ok elsewhere. Sounds like your sensor is working, and your car wouldn't run above ~16 afr, definitely not 22.4. So it's pulling in air from somewhere.

Question for the knowledge bank for future issues;
What would the AFR read when running on three due to one injector being stuck?
I.e. one cylinder just pumping air.
3x14.7 plus one 22.4 equals evil math :bang:

@curly: Thanks for the clarification! I have rigged up a flex exhaust pipe to bridge between the DP and the rest of my exhaust, until I can get a custom exhaust made. I am sure this is leaking some, and it is not too far (albeit downstream) from the O2 sensor.

I'm having the same issue, my mtx-l reads 22.4 at idle and when the rpm rises the afrs decrease. I wouldn't know what it would read when driving though, although on the stock ecu the gauge reads flawlessly.

You can't have that afr at idle because the car would stumble and die well before that.

Listen to the others and find the leak before chasing down other leads.

Exhaust leak within 2ft of o2 sensor of any size = useless AFR readings in low-flow conditions (idle)