gbbmk

iTrader: (1)

When I am on the throttle I go into pe or open loop. If i am only on it for brief min it will come out of open loop. However if I stay on at wot or a while the truck stays in open loop regardless of how fast, throttle position or just idle until I shut the truck off for a minute

I have tried working with my tunner guy and he is scratching his head. I have replaced the o2s and the mass is fine. I have long tubes with no cats. Cam intake and heads on a 2004 5.3 Silverado. I am at a loss. Has anyone dealt with this? What else can I look at? Map sensor?

Thanks in advance

BlackGMC

iTrader: (31)

Can you post the tune

gbbmk

iTrader: (1)

Unfortunately I cant. Bryan from pcm for less does it, I just monitor through torq. Sorry

smokeshow

iTrader: (16)

Can you see commanded AFR?

gbbmk

iTrader: (1)

No only o2s and ltfts

smokeshow

iTrader: (16)

What is the O2 voltage doing when it is stuck in PE?

gbbmk

iTrader: (1)

They goto 8.5 and the trims go to zero. Which is supposed to happen at wot but not after I back off
Thanks for helping btw

smokeshow

iTrader: (16)

8.5 or 850?

subeone

dfco will null your o2 sensors to read 0 +- trims. And COT will also make you read 0 +- trims, which dumps alot more fuel to keep your cats cool which could last a good while if you said you were wot 'for a while'. How long is that? 1 minute at WOT?

gbbmk

iTrader: (1)

Could be a min or longer.