I have a 1998 Ford F150 4x with a 4.6 w motor. I had a miss in my engine after a cold rain / snow night. Went to AZone after work and had the Scan . It said I had a misfire in cylinder 2. So I read some of the the notes on this site. I pulled the plug Motorcraft the out and it was black with discolored insulator. So i went back to Azone and got a new one and put it in . It started and ran great I think. I decided to go back to Azone and have it Scanned again thinking that the Computor would automatically erase the code ,but it was still there. Will disconnecting the battery clear the code ? Or the is the problem really still there .
If it is what should I check out.

 

You only changed on plug????????????
If I'd seen a plug that looked like the one you discribed it should have gotton the set. And some fuel enjector cleanor. How are the filters?
You will most likely have to have the colde cleared. Though the trucks computer will hold the code in it's memory.
Bob

 

You can disconnect the battery for about 10 min. and that should erase the code. The code willnot automatically erase itself. Though it will turn the CEL light off after a set # of drive cycles, the code will be stored and performance hindered until the code is finally erased. I would suggest replacing all 8 plugs with motorcraft(not autolight!). Usually a misfire under wet/damp conditions are going to be ignition related. Check your wires too. If they haven't been replaced I would strongly suggest doing those also. Once again, go motorcraft. Little more spendy but you will not have the issues many aftermarket wires and plugs have.

 

Yep ! only changed the one plug. I changed the orginal plugs at at 120K miles (truck was geting 15 to 16 mpg). So they have 30 K on these plugs.
It took me over 8 hours to change them . I'm an ole geezer in no shape to do it outside in wind chills of 0 degrees .
The truck is back to 15 to 16 mpg.
You suggested wires and I agree at 150 K miles . What kind should I get (Motorcraft) or ?
What else should I change? Coils ?