black2000ss

iTrader: (6)

I got into a new f-body recently. 01 heads and cam 6 speed. Previous owner claims to have done a speed density tune himself but the MAF is still in place and giving readings.
O2 sensor 1 readings are dead constant at .445v but sensor 2 readings are fluctuating even though it has no rear o2's.

Fuel trims short and long are constant at 0 under any conditions. Seems to run very rich, drivability is poor... Is the tune botched up that bad or does this sound like a mechanical issue? I don't have access to hptuners, readings were taken with a scanner. Let me know what ideas you guys have, you've always been awesome with advice

mrvedit

O2 sensor output is not dead constant, they oscillate. Fuel trims can be turned off.
As far as I know, you need to examine the tune to be sure you are in SD mode and that the MAF is completely ignored. (Correct me if I am wrong).
Have you tried disconnecting the MAF to see if it changes how the engine runs?

So far I think that O2 sensor 1 is defective and that your tune is not optimal. You could start by replacing the O2 sensor. If you think you might get into tuning, you might consider a wideband O2 sensor and gauge. The AEM and others can send an narrow-band signal to the PCM so that you can replace one narrow band O2 with the wideband setup.

BBC632Camaro

iTrader: (82)

Could try swapping sensors bank to bank and see if it reads the same or if the other side reads what the first one did and then you'd know its the sensor.

black2000ss

iTrader: (6)

Thanks for the replies guys. I figured it out. The p/o did not swap pins with the o2's when longtubes were installed. The rears were the only o2's in place, no front o2's at all. I swapped pins at the ecu rear to front, and guess what. Working fuel trims, and working o2's!

mrvedit

Excellent. And thanks for reporting back with the solution.