I have a 1997 GT, 5 speed,convertible with 69k on it. When I accelerate hard it sputters or skips when I first punch it. The car idles fine and runs smooth but I can't seem to figure out the problem I haven't replace the plugs or plug wires in about 30k miles. The fuel filter was replaced last Fall and I ran injector cleaner through it in the Spring. This problem was present during the Summer last year but I couldn't resolve it. Any suggestions would be greatly appreciated.  

There is a simpler solution then trying to figure out whats wrong. Get an OBD2 reader and read the codes. Your car is equipped with on board diagnostics and it will tell you whats wrong with it. Hook up the reader and download the codes and then you will have an idea.  

I took my mustang to a repair center to have the cars State Inspection done. They hooked up a reader to the diagnostic port under the dash. There were no codes present. Got any other suggestions?  

Well if there are no codes present, then your car is running the way the factory calibrated it. It is possible that a code hasnt shown up yet because some of them take two or three (Missfires) incidents before there is a code written.  I think I would have the dealer run it on his diagnostic machines because they read more then then just codes. If you can replicate the problem on the way to the dealer all the better because it will be in memory.  

I guess that is the only recourse that I have. Unfortunately, I haven't found a dealership in the area that I can honestly say that I trust to work on my car. There have been 3 that have gone out of business in the last year. Most are a fair distance away now. I have to do some research to see which one might be the best and most trusted.  

Have you tried cleaning your MAF?  

No I haven't tried that yet but I will. At this point I'm not sure what to do so any suggestions are a great help.  

check your mass air flow meter or TPS. The TPS is easy to check find you reference wire usually green and back prob it and use a volt meter (digital) turn on the key engine off and then raise the throttle and you should read .8 to 1 volt throttle closed up to 5 volts wide open. If it glitches or falls in any way on the way open then it is bad. It could also be an EGR valve opening to early too. You will just have to check. Hope this helps