Lost power after new PCM is used?

[blk97z28]

Well to make a long story short I have Pacesetter headers and then a offroad y-pipe with a turndown on it for my exhaust system. My question is I got a tune and I put down 266 RWHP and 293.3 RWTQ, so the dyno man told me to go take it out and see if it shifts (auto trans) at 6250 RPM so I did I got on it at about 30-35 and it took me sideways. I then tried WOT at about 40-50 and it pulled a lot harder then before, so I went back to his dyno shop and I got a check engine light so while he was clearing that code my car shut off so it fried my PCM. He got me a used one a 97 camaro z28 A4 and it has worked good. But NOW when I floor it at 30-35 and 40-45 it does not pull like to did before my PCM got fried? WTF is going on? Could a PCM that is not set for my car correctly cause this or not? He saved all my TUNE settings on his laptop and he reloaded my tune into my PCM so I don't see where the problem lies? Can anyone help me out on this one. I got a new check engine light now so when I go back to my dyno man should I have him look at why I lost power (feeling of losing power) in the MPH ranges that I said above. Thanks for all your guys help! Any suggestions are welcome, give me all your ideas guys!!!

[roo]

They run the best right before they blow.

[blk97z28]

HAHA

[roo]

So did you put it back on the dyno after you reloaded the tune to confirm you were down on power?

[clint]

Just talk to Dan and tell him your concearns. He will treat you right.

[blk97z28]

I didn't put it on the dyno again, do you think he could do a quick dyno run for me? Dyno Dan is a great guy he said just bring it down and we will figure out what is going on.

[clint]

I would be surprised if he didn't put it back on the dyno to see if you did indeed loose power.

[blk97z28]

Thanks!:)

[David]

what dyno were you on the first time? or did i just mis read that.

[blk97z28]

Dynojet.

[CustomSSI]

it could be a completely diffrent tune on the computer than what you had. Have him reflash it

[C.J.]

its all in your head

[blk97z28]

Well found out tonight that BANK two 02 sensor is bad, I need to replace that then Dan said we will throw it on the dyno and see what happens.

[Jasen]

O2 sensor failing will not affect WOT performance. Narrow band O2 sensors only have an affect on stoichiometric performance, i.e. idle and cruising at steady throttle. The PCM ignores O2s at WOT and uses MAF, MAP and throttle position to insert fuel / timing values based on the lookup tables (tune) stored in the PCM for given sensor values. The only exception being the heater circuit shorting to the 5v VREF circuit can cause a 12v VBAT back feed into the VREF 5v creating many driveability issues.

[C.J.]

O2 sensor failing will not affect WOT performance. Narrow band O2 sensors only have an affect on stoichiometric performance, i.e. idle and cruising at steady throttle. The PCM ignores O2s at WOT and uses MAF, MAP and throttle position to insert fuel / timing values based on the lookup tables (tune) stored in the PCM for given sensor values. The only exception being the heater circuit shorting to the 5v VREF circuit can cause a 12v VBAT back feed into the VREF 5v creating many driveability issues.

exactly

[blk97z28]

He said it was malfuctioning, are yes 02s are not taken into account at WOT i know that, well we will see when it gets back on the dyno.