First as the FNG let me say hello to all...

My wife drives an 02 Tribute LX with the V6 engine. Currently has 71000 miles. She bought the car new right before we met. I have always maintained the car.

About a month ago it started missing. There was a code, which the code reader reported as P0305: Miss on cylinder 5. At this point I changed the plugs, and the problem disappeared....till tonite. I'm in MD where we just had a little ice storm. I went out to clear the car for her. I let the engine run while I was cleaning the ice. It ran for 5-10 min and I jumped in to take it up for a fill-up. At this point I notice a severe miss, and the check engine light is flashing. The miss seems to be intermittent (sometimes the check engine light is on but steady), but when it's missing, the car is almost un-driveable. So I check the code again. This time P0304: Miss on cylinder 4. I pulled the plug; it looks fine. Nothing visible to report on the coils, appearance-wise they look normal.

Any ideas on what might cause this miss?? I'm beginning to think it will need a new wiring harness.

 

Moisture is most likely the problem. The plugs are recessed and moisture and sometimes water can get into the recess causing a short. Even though your coil packs look good they may need replaced. You can buy aftermarket coil packs online pretty cheap. I replace both the coils and plugs each time just so I don't have to worry about it for a while. The front plugs and coils are easy, but the rears ones are a pain.