2003 grand prix, 3100 v6 obd p0303

my friends grand prix 2003, tripped obd code p0303(misfire one cylinder #3)...i changed the plugs, wires the 3,6 coil,removed the intake and checked and cleaned all fuel injectors(checked to see if gas was spraying out, and voltage test, all ok) checked commpression, also ok......the only thing that i have not read on all the other posts is the car is making a loud ticking sound, maybe a bad intake lifter, the plug on cylinder 3 is not wet or does not smell like gas, also the oil is clean.....any ideas..oooo also checked o2 sensor its good, cat converter making a rattling sound ...the car has 80,000 miles.....any ideas...thanks drac...

Yeah repair the conveter it's likely restrictted and that will lead to a misfire!

one of those days, changed fuel injector, had a cat converter put in and still a f@#king misfire, p0303 code, it still idles ruff......any other ideas??????thanks drac

intake gasket leaking? ignition module problem? cylinder leakage test! is the injector being pulsed?

***the intake this car had, had a crack by the alternator bolt, so i replaced it with new gaskets, i checked the fuel injector wiring with a noid and voltmeter the power was within specs. ,checked the pressure regulator, replcaed the fuel filter, the fuel pressure was 55-65psi, tomorrow if i have a chance i'll check the module, i also heard that a faulty crank or camshaft sensor could cause a misfire???? what do i look for when checking the module besides cracks???? thanks for your help jeff....drac

if crank sensor why only 1 cylinder?

jeff, today i replaced the module, reset the p0303 code within 30 seconds the misfire on cylinder 3 (P0303) reapeard, the tickiing sound is still there, thanks agian...drac

The only other thing I remember about those cars is egr problems and the port under the intake plugging but it'd be a stretch I'd think to be the cause of just 1 cylinder misfrie! Was the code there before the intake job?

*****GUEST WHAT....TURNS OUT IT WAS A BROKEN INTAKE VALVE SPRING.....THATS WHY IT WAS MAKING THAT TICKING SOUND....DRAC

Thanks for the update.