O2's going bad? Really need some help here people....please take a look.

[camaro28]

OK, basically what is happening is the car stumbles all over itself. Its a 5 speed car, and form a stop, if you dump the clutch and floor it, you get a loup Bang form the drivers side cylinder bank. It doesnt do this if you ease into throttle. Also, while cruising, at apporx 35-45 mph, usually in 3rd or 4th, if oyu floor it, it again has the loud pop, and then seems to misfire for a bit after that. There is nbo pop or misfireig if you downshift frist, before applying full throttle. The backfiring is not always accompanied by a SES light. I have read that if the O2 sensor goes in the 3.4L engines, the ECM automatically runs it rich, as opposed to a lean condition. Is this true? COuld a bad o2 be my culprit?

For the record, Mods include: KN CAI, Flowmaster cat back. doubt any of these would affect it, but who knows.

Also, the cat. converter is gutted, however I think my o2 sensor is before the cat, so that would not matter. Any suggestions are welcome! Im tired of driving the thing this way.


28

[David Blalock]

If the O2 goes out it just dumps fuel into the engine. I know, I just pulled mine out sunday and it was completely black. Don't just pull it to check it though, they are very very sensitive and will almost certainly be broken by taking it out. Is gas mileage bad too? That's another sign of a bad O2, like a 5-10 mpg drop. Have you pulled the code yet? I'm rambling a bit but today was long and I'm exhausted, good luck trouble shooting.
David

[silicuda]

If your O2 sensor is broken, and u hookup an engine scanner to your car will the scanner tell you?

[Wolfy]

i had a similar problem with my 3.8, twice. the 1st time it was jsut a burnt wire, so i had all them changed as well as the plugs. next time it was a coil pack, and that caused the plug and wire to burn up again. i would definitly say its ignition related, cuz they usually show up when the motor is under load, like when you floor it. that is what i would check for first.

also it never hurts to change your o2's, and fuel filter, and all that good stuff.

good luck [img]graemlins/thumbsup.gif[/img]