85 mpfi, runs great till it starts to get warm, about 2 minutes, then starts missing, and backfires through the intake. im about to shell out 30 bucks to test the think. im not finding any usefull codes, does this sensor sound like the culprit? has anyone changed one and had thier car run better because or it?

Are you running an 02 Sensor? Sorry for the strange question but I always thought that running without it would give you very similar problems. It runs without feedback from 02 sensor on most cars for about 2 min and then the sensor leans/enrichens the mixture based on the temp and 02 sensors.

ya, i was runing without an o2, for lack of a hole in the exhaust, for about 2 months, and it ran fine. morganm, has no 02 sensor for about 20k now, with no ill effects, other than poor cruising economy.

the problem started after i put on an o2 sensor, and new exhuast, and i cleaned the flapper maf. and the computer supposedly doesnt even look at the o2 sensor at wot, and it still craps out floored, or idling.

my car runs so bad now that i cant move it from its parking spot, but it goes great till it starts getting warm.

 

i have no fsm, would that tell me how to test the sensor with an ohm meter? im guessing it gets something like 4 or 5 volts, to it, then is sends back to the computer, however hot it is.

i have tried unplugging it, but i havent tried jumping the terminals with a wire.

anybody know anything about efi at all? guess its over to the aussie board

Aussi board?