Can driving for a year with a misfire cause major damage?
I have an 05 F150 5.4l 4x4. Last year some stole my catalytic converters, since I only carry liability insurance I could not afford to fix this right away and drove for a year with a welded in straight pipe and only the upper O2 sensors. Of course it began to run like crap after a couple of months, with lots of misfires. I recently replaced the cats and installed new O2 sensors (all 4), and while the truck runs much better now #1 cylinder OBD code P0301) is still misfiring under load. My next move is to replace all the spark plugs and the coil pack on the #1 cylinder. My question is could I have done any major damage driving like that for a year?
Have you ever had the check engine light flash? That’s when the catalytic converters are being trashed by unburnt fuel. The longer you wait to fix a dead cylinder the more you are risking those new cats.
Quick test to see if it’s the plug or the coil just switch coils between 1 and 2. If it follows it’s the coil. If not it could be the plug. If you change the plug have the lisle extraction tool available, on cylinder one with the easy access you can have it out even if it breaks in a few minutes.