Lean idle/cruise AFR's after hard pulls.
 

I ran into this issue first after making a couple of passes down the track. After a full pass down the track and I let the car idle following the return road the AFR's would read high 14's-low 16's..the car notable missing a bit more, rpms hunting. Normally the idle would be in the high 13's-mid 14's.

The voltage to the wideband is good, sensor is new, o2 tapped correctly on the downpipe @ 3pm position, no leaks @ the sensor where it connects to the DP,wiring and settings on the AEM are good. AFR's during the track passes were low-mid 11's right where they needed to be, timing good.


Anybody else encountered this problem? I didn't encounter this issue just doing hard pulls from rolling in 2nd gear. Maybe there's a setting on the AEM that's needs touching up? Any insight would be appreciated...thanks!

Jorge R.

Is O2 feedback enabled? And if so, what are the percentages? Perhaps you are beyond feedback correction. And if that is the case the other thing that comes to mind is your air temp correction table is not configured correctly, and the higher intake temps after a full run are affecting your AFRs.

O2 feedback is disabled, but I'm definitely going to take a look at the air temp correction table..great suggestion..Thanks!!

I dont have aem, but have the same problem with the lean idle after hard pulls. Bump for help.

Also what fuel are you using and are you switching to and from different grades. Like 100 to 93??

I did see that the air temp correction is a little off. But I didn't think it was off by that much.
-Where do you have the sensor mounted?
-What is the temp like? What does the sensor show before and after?
-If anything I've observed the hotter it is outside the richer the car runs. Hot air needs less fuel because there are less air molecules.

Let us know if it helps. I'd be interested in knowing.

I'm running 100%meth with both pump/race maps. It hit me today that maybe the AIT sensor is too close to the meth nozzle. I have the AIT sensor before the meth nozzle, but only about 3-4 inches apart. I'm going to get it relocated this week. I hope that's th culprit!

I don't know much about Meth and where to install the sensor.. that could do it and drastically change the temp.

Can be your injector duty is too high on "hard pull" and they are overheating, so the coil in the injector is making lower magnetic field and this means it opens the nozzle not so much like when the injector is cold.