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

 

Can you post the tune

 

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

 

Can you see commanded AFR?

 

No only o2s and ltfts

 

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

 

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

 

8.5 or 850?

 

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?

 

Could be a min or longer.