Lean AFR when cold

warracer

New member
Okay,

Im having an issue with my st185. When the car is cold, the afr is extremely lean. We're talking 16-17:1 afr when cruising, but as soon as the coolant temperature neddle move ever so slitghly, im back to steady 14,7:1 when cruising and 11-12:1 when WOT. Im running bone stock ECU, bone stock MAF, and I was wondering what could cause that, O2 sensor? Temp sensor? :shrug: Any help apreciated

Thanks! :)
 

warracer

New member
loudstealthGT-Four":3bigwf64 said:
Whats the AFR at WOT when cold, wouldn't worry too much about the AFR when cruising.

It starves for sure, if I WOT when cold (which I never do) aprox 16-17:1 but I never builded up boost , I don't want to blow it up haha
 

MWP

New member
I wouldn't worry about it.
An AFR that lean won't hurt the engine at all at cruise, or even light acceleration.
It'll feel a bit powerless, but thats all.
 

warracer

New member
MWP":28g33vkg said:
I wouldn't worry about it.
An AFR that lean won't hurt the engine at all at cruise, or even light acceleration.
It'll feel a bit powerless, but thats all.

Oh ok good, I was getting worried about knock maybe, but the CEL never came on and the car works perfectly fine after it reached temp.
 

klue

New member
lean afr when cold could simply due to poor fuel atomization. dont worry about it, just avoid heavy load.
 
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