Misfire in my 98GTP (HELP PLEASE!!!)

[braka72]

Hello,
My 98 GTP recently had the SES light come on for the first time. It started flashing (indicating misfire) and then stays on solid. Went to Auto zone and the code showed misfire in #3. Cleared the code and drove home. I have tried pour in injector cleaner and the light has since came back on. I dont feel it was bad fuel. Had the car re-checked with the same code showing.. It seems to run fine at idle or lower rpms but really starts to miss at higher rpms. I feel it may be either the injector for #3 or possibly a coil pack. Can someone tell me how to check the coil with a meter if possible? What resistance will I need to look for (primary and secondary). Also I have already installed plugs and wires with no change. I have not done a compression check(yet) because I dont feel it is mechanical. The engine runs too good at idle and if you keep your foot out of it it seems to be fine,(smoothness,fuel mileage). Any help offered will be greatly appreciated.
Thanks,
George

[Ripn12s]

not sure exactly how to check the coils, but you could pull #3 injector and swap it with a different injector and see if the missfire moves