Hello,


I have a 1999 Mustang with a 3.8l engine and it is showing a misfire on the #4 cylinder. I have replaced the spark plug, have swapped the spark plug wire with another cylinder and have replaced the coil pack. When I replaced the coil pack the check engine light went a little over 200 miles after resetting before coming in again. Otherwise it has been coming in around 50 miles after resetting it. The only thing else I can think of is the fuel injector. Anyone else have any ideas?

 

check fuel injector for proper operation and check compression of that cylinder... i also wouldnt count out the new coil being bad either. ive been burned by new bad parts more than i care to remember