Thread: Bad Mileage - 02 sensor? Stock Live Data List?

I have a 04 GTP. Replaced the engine about 40K miles ago and has preformed without any issues. In the past 6 months, mileage has dropped from 21 to around 15. No codes listed, but the 2nd OS sensor (after the cat) was reading 0 V. wiggled the connectors and it seemed to come back online with readings between .1 and .8 or .9. I cleaned the MAF, made sure the ECT sensor was online. Hoping this is going to take care of the problem.

It's interesting to me that there are no codes...In two cases in the past when I've gotten on er, everything shuts down and I get the "Reduced Engine Power" message. Turn it off and on and it resets and is fine. Still, no codes. Any thoughts? I was having multiple misfires in the past but changed plugs and wires and they went away.

Also, where can I get a listing of stock Live Data Readings for this car? I'd like to go through the live data and see if I can find anyting out of line.

thanks much.. Brent

Accelerator position sensors or tps not agreeing will cause reduced engine power and I think a transmission fluid over heating would also cause reduced engine power.. check those things.. there is s tsb on 04 plus 3800s for moisture getting into the plug where the wires from inside the car go out to the engine compartment. Pull back the carpet on the front passenger side seat and you will see the wires