Probably about a week after I had the exhaust replaced (original exhaust @ 16 years old and 207,8xx miles), the car was not idling normally and eventually the CEL was triggered. I was wondering if this was coincidence or was it related to the exhaust work that was done. I decided to try my hand at diagnosing the issue and picked up an OBD II scan tool and received the P0301 code. I then swapped the ignition coils between Cylinder 1 & 3 to see if it was a bad ignition coil. I cleared the code and started the car up--still not idling normally--and this time received the P0303 code. Placed an order on RockAuto for Hitachi IGC0007 which is listed as OEM and am hoping that this will address the issue of an otherwise, trouble-free ownership!

 

Did you have any oil in the spark plug well tube on cylinder 1? It can cause premature failure of coil packs along with other potential problems.

 

Thanks for your reply, @cleric670@gmail

If I understand your question, when I removed the ignition coil, the spark plug well tube was clean--no oil residue along the walls of the tube nor on the spark plug terminal or insulator. I did not remove the spark plug in cylinder 1.

 

Ok I would pull cylinder 1 spark plug and inspect it, P301 was a misfire on cylinder 1. Just to verify there wasn't something else going on that caused the coil pack to fail.