I have an 89 lx, i just installed an offroad h-pipe changed my oxygen sensors intake temp sensor and iac valve. My car is now backfiring like crazy even on idle. Really loud backfires. i turned down my fuel pressure but didnt do anything any ideas?


my car has some mods if that makes a difference? trick flow upper lower intake, x cam .542 lift, 1.6 roller rockers, bbk 70 mm throttle body, 24 lbs injectors,bbk mass air flow,msd 6al to name a few.

 

A gasket leak at the iac maybe,or one of the O2 sensors maybe no good even if it is new.

 

it ended up being a two pcv vac lines that came out when we lifted the motor to put on engine mounts

 

Glad to hear you figured it out