Tuning

[98Z28]

I had you and Brian tune my '98 camaro last summer. It had both O2's flat lining at idle, but come back on when you hit the throttle. Since getting new O2's, would it be worth my time to have it tuned again? If so, are you willing to tune it, or is someone tuning for Shelley's?

[twotons]

Not Speeking for Marty, but if you would like let me know and we can just throw it on the rollers and check everything then tune if necessary, we have all the HP stuff at the shop. I ff i remember right, Marty was tunning of the dyno imfo more then what your O 2's where reading so it may be real close on the WOT tune.

[Evosol]

Generally, the o2 sensors are in closed loop in low load conditions, and then open loop in high load situations. So Brian is correct, WOT should be not have changed, but depending on your fuel setup, partial throttle might require some cleaning up... , not say that the o2's won't try to pull and maintain a/f in the stoich range, but then again there might be some type of long term fuel trim routine and that might shorten the life of the o2 sensors. So yeah, it might be a good idea to clean up partial throttle cells.


Geez... its been a long time since ive thought about EFI stuff... kind of miss it.

[trbo355]

I remember your car having weird O2 readings. I think it was the right thing to do by replacing them and like Brian said, all the WOT stuff was tuned using the dyno's wideband so you should be fine.
The GM oxygen sensors are notorious for reading a different voltage at WOT between different cars even though the A/F may be tuned the same. It has something to do with sensor placement (headers or stock manifolds) and sensor temperature so the dyno's wideband has been the most reliable way to do it anyways.
It might not be a bad idea to have Brian datalog it to make sure they are switching correctly and there isnt still a problem like maybe a small vacuum leak haunting you.