Engine running badly!
I have a 1998 Ford Mustang GT Convert. 4.6L... it has been missing for the past few months... we have changed the fuel filter a couple of times, the air idle motor, the spark plugs, wires and the call packs and still the car misses... this is not a continue situation, it comes and goes... does not always run badly. we did go from the "h" pipe with converters to the straight "h" pipe without... took it to a repair shop twice and the car ran fine and they couldn't fine the problem. I'm a faithful MMFF reader and was hoping that someone may have the solution to my problem with my car. Please let me if anyone has had any problems like this... I don't know what else to try. HELP!

Robert Elizondo
Dayton, TX  

is your check engine light on