GMC Repair: 1999 Grand Am, cylinder misfire, pontiac grand am

Question
I have a 1999 Pontiac Grand-am and it is running rough.  i had it hooked up to a computer and the diagnostics came back as a cylinder misfire and fuel injector malfunction.  The plugs and the coil pack have been replaced, but neither one helped the situation.  can you give me any more things to take a look at or could you tell me a rough estimate about what a mechanic will charge to get the problem resolved.

Answer
hello rob
a shop would do a good diagnostac test . the price of that is 50 dollors . and the problem would be repaired the only thing the repair would cost you around 200 dollors at least it is the best way to go if you keep guesing it could cost a lot more pete