car starts up runs for 15 seconds smoothly but wont rev up with out spits sputers and backfires after stainless early exhaust installation

 

hi, you said you fitted early exhaust system to the car. does the new system have a slot for an oxigen sensor, if not then that is your problem, you need to have an oxygen sensor fitted to your headers. whatever the case is I would start from checking or replacing the oxigen sensor, because it sounds like that is the problem, maybe you damaged it while removing the old system.

 

I would double check your CO, sounds like you probably have a lot more air flow now, and are running a bit lean.

 

bought car from penske in 1988 and never had a o2 sensor in stalled