I have 1999 Ford Explorer Sport (manual) and I have a check engine light on and off for some time now. I had AutoZone check it and it returned a code of P0303. I had this code again like twice for the year. I had the spark plug changed # 3 spark plug then had all the spark -plug wires changed as well. A few days later I get the code again. So what else could be the problem? The AutoZone said it could something wrong the cylinder. Any other thoughts on what it could be?

 

I have a 1997 Ford Explorer Sport 4x4 that had #6 misfire code. The plug looked fine, but changing it resolved the problem. I purchased the SCAN tool and erased the code. It has never returned.

Your Sport should perform badly (running on 5 cylinders) if indeed that #3 plug is not firing. Are you sure you have the plug wire fully conneted on the plug and at the distrubutor? It can fool you sometimes as the fit can be misleading to have full engagement. You may have a gap at one end or the other and it will fire fine most all the time, but when under a heavy load, it may misfire for a few beats, store the code and then go back to running normal!

 

well everything runs smoothly now, no longer getting the check engine light or misfire code.

 

check your coil maybe it is there the problem is at