prowlingleather

Posting before actually doing a thorough check, as annoying as that is I'm sure, since I've only got about 3 days before I have to drive this damn car back to college...

I replaced the upstream O2s on my 98 Trans Am about two months back after the codes first showed up and they've been reappearing since then. Car drove fine for the first 100 to 150 miles of my straight shot drive to Houston; after that, once she warms up properly, she starts having a "choke"--a kind of pulsing where she seems to stutter when accelerating (kind of like what she did before I replaced the fuel pump and sender unit) that usually goes away if you cool her off and turn her on again. It disappeared completely when I drove her while it was in the 30F to 50F range.

Today, on my drive home, it got so bad I ended up limping part of the way home at 5 mph. When I hit the accelerator, the revs will swing up to no more than 2000 rpm and the car doesn't speed up at all; when I let the pedal go, it lurches forward. Rinse and repeat. Exhaust is all stock and probably untouched since 1998.

I did a dig through the forums and I'm going to definitely check the wiring tomorrow; I've got an iffy plastic-burning smell as of late by the front driver side wheel well that I'm highly suspicious of. I've also got a bit of a rattle somewhere in the exhaust, but it doesn't sound like the cats are broken up (if anything, they're more likely to be clogged; I may or may not pull them off and look through them tomorrow).

Any chance that it could be anything but a dead/dying O2? Any info I could check with a cheapie OBD2 scan? (Vacuum pressure at intake seems alright from a quick test after I got home; I'll check again more thoroughly tomorrow)

Thanks in advance, guys!

roadhammerr

Sounds like the TPS sensor isn't working right check voltage at idle should be 0.54 volts and goes up almost 5. volts at wot..