Check engine light codes problem with my 2002 Pontiac Grand Prix GT.
Engine size = 3.8L non supercharged.
ABS, Track Off and Service engine soon.
GM Computer codes = C0045, C0046, C0245, P0303, P0420, P0172.
Repair work done prior = Reason for code P0420 is because I dont have a catalytic converter.
Work done to repair this problem = Ever since I retreived the code P0303 I have changed all of the spark plugs,fuel pressure regulator, fuel injector for cylinder 3 and switched around coils but still got the code for cylinder 3 misfire.
Question = I only get a misfire when i step on the gas and when i do this my SES starts to flash. OBD code reader reads P0303 cylinder 3 misfire. To correct the problem i have changed out all 6 spark plugs, didnt change the wires because they are working fine. I have switched up the coils to see if it was the problem. So i switched them up and stepped on the gas and again i got a blinking SES light and code reader gave me P0303. I changed the fuel injector for cylinder 3 and still no solution. I also changed the fuel pressure regulator and the oxygen sensor
behind the engine on the manifold. I also noticed that after i changed the spark plugs i looked at the one from cylinder 3 and it had little cracks and looked kind of smokey. I changed it and a few days later the same thing happend. As for the ABS and Track Off light on I got the codes C0045, C0046 and C0245. What do these mean? What could the problem be for my misfire?