04 mustang gt help!!

[gabe2282D]

So I have a 04 mustang gt with a jlt cai,mac pulleys,3.73 gears,dual friction clutch and I've been running the 93 tune that comes with it and after 4 months of running it my car started to misfire in all cylinders so I took off tune and now runs great again.do I need a custom tune or? Coils look good and spark plugs are 4 months older haven't taken it to a dyno because I don't think I have enough modifications for that.I tried reflashing and after 10 minutes check engine light comes on and runs rough again any help is appreciated

[mikel]

Nothing in the tuens would cause a misfire, there has to be something else contributing...

[gabe2282D]

What would u recommend doing? I know if I Stand near the exhaust I could hear a few light pops so it sounds maybe electrical .I wasn't getting a check engine light with stock tune until tonight the check engine light came on and was reading multiple misfires from 4 cylinders what would be ur next step? New coil packs? Clean injectors?

[mikel]

tough to say, coils, wires, plugs...

[gabe2282D]

Thanks mike ill try it