I have a 99 gt minor mods include o/r flow masters throtle body and intake upper all performance products . I had a bad coil so instead of a continual problem I changed them out for a new set of msd ones the service engine light will not stay off it says it has a random misfire help please

 

check ur plugs or maf sensor

 

not sure, i had misfire with my msd coils too that just went away by itself and hasnt returned. definitely check you plugs to see whats going on. also, check you connection to the coils to make sure they are on securely and also when you check your plugs, check to make sure the coil spring inside the coil is also secured properly to the coil.

 

A bad/dirty MAF will cause random misfire codes on several cylinders.

 

not that I think this is related but, you say O/R... are you referring to an off road H or X pipe? if so that is going to trip the MIL light with out MIL eliminators or a tune.

 

I cleaned the maf last week trying to get the light to go out . Checked the plugs ,made sure the coils where all the way on tight,cleaned the filter which is a KN , ran two tanks of concentrated fuel cleaner thru the tank with high test , And today the light went off all by its self . Dont know what worked but the light went off and the car runs alot better it feels like it has 20 more HP . Thamks to everyone Scott