random lean condition

[blown 04]

Can someone please look my scan from yesterday and maby give me a idea on how to stop a lean condition that just happens once and awhile. I also posted my tune. I have changed o2s and maf, nothing helps.

thanks Benji.

[Frost]

Are there DTC's when the FTs stop updating? It looks like it's moving in and out of closed loop but it's odd that the STFTs hang on at their last value rather than returning to 0 as you'd expect in OL.

[blown 04]

no dtc's when this occurs, im hopeing someone here can maby point me in the right direction. Seems like it will do it if the truck sits and idles for couple
min.

[Frost]

Check and make sure that the heater ckt is good to the O2s. Do you have LTs?

[blown 04]

I dont have headers on now,all stock manifolds and cats. my truck is FI just to let you know if that helps

thanks Benji

[Frost]

maybe log the closed loop status bit and see what it shows as it happens, like I said, except for the STFTs not updating, it *looks* like OL

[blown 04]

thank you for trying to help me, this problem is driving me crazy. i will log closed loop for a while. if its that can it be fixed or adjusted?

[ChrisV 02 - Z28]

My camaro does the same thing, it will idle fine but let it sit there for a while idleing and the AFR will start going from 14.7 area to like 18:1 for no reason does it both in closed loop and open loop. I know the AFR is getting lean from the change in idle sound through exhaust