95stang gt

hey guys so for the past couple weeks my car has been backfiring when i down shift. could this be an 02 sensor problem? what else could cause the car to go lean and backfire? thanks in advance

golden_eye

Not sure if this would be the same problem but after installing my O/R pipe the car would backfire when upshifting hard into 2nd. I did a decent tune up (cap, rotor, plugs, wires, coil) to try and fix a separate misfire issue and now the car doesn't backfire anymore when shifting. It was probably the cap/rotor and the plugs that helped the most because the cap had a ton of carbon buildup on it and the plugs had about .62 of gap when I took them out.

mjr46

does it actually backfire or just popping/rumbling??

95stang gt

no it backfires. only when i down shift at high rpms though.

Canary94GT

Do you rpm-match? It's not so good (on your tranny) to straight downshift to a lower gear in high rpms.

95stang gt

rpm match? u mean double clutch? thats what i usually do. i was teaching my buddy to drive a manual and i down shifted(not double clutch) and it backfired and thats the first time it ever did it.

mjr46

check the thermactor air system and make sure the check valve/ anti back fire gulp valve that screws on to the air tube that goes to the heads is not ruptured