Causes of high STFT's

[Ben Charles]

Trying to tune my procharged Trans am and something I am seeing when the car warms up (190-210) is that my STFT's on the drivers side is around 50 and passenger is high too (to be honest I can't remember) before I post a log/scan I was wanting to get some ideas on what may be causing this?

From my understanding its a lean condition somewhere (possible vaccumm leak) and the ECU dumbs fuel to compensate.

Possible reasons I came up with
Header/head leak
exhaust leak near 02 sensor
Intake manifold/head leak
Leak after MAF to TB
Fuel injector to manifold

I have check the above and everything seems to be ok, me and my friend don't believe that could ever be a tune issue and it has to be mechanical?
Anyone have any other ideas?

[Google]

Trying to tune my procharged Trans am and something I am seeing when the car warms up (190-210) is that my STFT's on the drivers side is around 50 and passenger is high too (to be honest I can't remember) before I post a log/scan I was wanting to get some ideas on what may be causing this?

From my understanding its a lean condition somewhere (possible vaccumm leak) and the ECU dumbs fuel to compensate.

Possible reasons I came up with
Header/head leak
exhaust leak near 02 sensor
Intake manifold/head leak
Leak after MAF to TB
Fuel injector to manifold

I have check the above and everything seems to be ok, me and my friend don't believe that could ever be a tune issue and it has to be mechanical?
Anyone have any other ideas?

dead cyls or exhaust leak.




.

[Ben Charles]

Just want to add, I had a Intake manifold leak (replaced gaskets) and I also replaced new 02 sensors with GM Ac delco's. I never reset the fuel trims, is that required??

I have wideband now and I want to get everything in check first, but next step is to disable STFT's and LTFT's and to do tuning. After tuning plan to keep the LTFT's disabled, only need STFT's.

[Ben Charles]

Google we do know its firing on all cylinders, I will check for exhaust leaks with some carb spray next.

[Google]

Google we do know its firing on all cylinders, I will check for exhaust leaks with some carb spray next.

Like playing with fire? not intake leak or vacuum leak.. EXHAUST leak.. That carb spray won't help keep your car from burning..




..

[Ben Charles]

opps your right, thats only on the induction, lol my bad