I have code p0303 on for cylinder 3 and i checked the coil going to cylinder and it did have an intermittent spark to it and so naturally i changed it. But i still have the code on and the car is still running rough when in drive and at idle or even picking up speed. Need help. Thanks.

David

 

It could be as simple as a bad spark plug wire or control. I once had a misfire code for cylinder #5 and it was due to spark plug wire (plug end) swelling from an oil leak into the plug well. That made the wire pop off the spark plug and causing an intermittent misfire. Also, check wire for the other plug that feeds from the same coil. Both sparks on single coil fire at the same time and it is possible that the other cylinder is the one with the problem. Look on the intake manifold for cylinder numbers which correspond to the coil. Don't forget to check the primary coil feed wires. Make sure the connection there is good and you have signal.

 

k thanks will give it a try.