IROCThe5.7L

I had my BLMs dialed in when I just had the heated narrowband. I recently installed a wideband. And the wideband is pretty much telling me the same thing. The only issues I'm having is when I datalog, I'm seeing a lean condition at idle when warm and in closed loop. Yet the wideband is reading mid to low 13's. I lowered the value I idle at in MAF table 1. And it seems slightly worse or the same. Is this because my narrowband is reporting a lean condition and its dumping more fuel in?

Also, when I let off the throttle and coast to a stop. The datalog shows lean. Yet my wideband shows very rich around 12.5. The narrowband is in driver side header. And the wideband is on the passenger side. No exhaust leaks. Part throttle and pretty much normal driving is great. The wideband shows high 14s and my BLMs are right around 128.


Thanks for any advice.

JP86SS

iTrader: (1)

Sounds like an air distribution issue (split BLM at idle and closed throttle)
I have seen it change with different IAC openings on mine.
Set your TB blades open or closed a bit to make the IAC opening more or less and see if the readings change.
More IAC air smooths mine out, might help your setup as well.
RPM will remain the same, just making air take different paths (TB or IAC)
Jp