Engine Performance problem
2002 Ford Taurus 6 cyl Two Wheel Drive Automatic 74000 miles
I have an engine miss at idle. Miss started after replacing spark plugs. Had to also replace upper plennum gaskets because had to take that loose to get the back plugs. Ran fine for about 2 weeks. Then a minor miss started. In gear at idle. Then the miss got worse. Turned engine light on. Had P403. Removed the upper plennum and pulled #3 plug out. It was fouled. Replaced the plug and the coil, because it had a crack in it. Thought that was my problem. It wasent. Still have miss. Not missing under load like plug wires would. Worse when it is a cold start. Cant find a vacuum leak. No codes.
Engine running rough or misfiring can be cause by the following: 1. Defective spark plug.
2. Inadequate spark/coil, defective spark plug wire.
3. Lack of compression
4. False air leakage.
5. Faulty fuel injectors.
6. Insufficient fuel pressure.
7. Contaminated fuel.
8. EGR valve that is leaking.
9. Oxygen sensors.