This happened today, drove to work truck fine, went to lunch truck fine, started back to work, truck not fine. Horrible miss in engine, got back to work, pulled out the OBD reader, it told me Misfire detected #1 cylinder, ok, I changed plugs about 2000 miles ago, used NGK tri-powers. Got off work limped home, took out the plug it looked fine, but there was a vertical shadow on ceramic, and a horizontal shadow down next to base, I took that as being hair line cracks, I just happened to have an old motorcraft plug I took out previous stuck it in, the miss is gone. Now I will go and buy 1 plug. I will probably get some weird looks when I ask for 1 plug for a V6.

 

Found this on my 1,000 mile engine....horrible miss under load....no codes thrown. Ran good unless under load.

 

Yeah that plug looks bad, mine was just a shadow. Weird HUH

 

Well, replaced plug truck ran fine until, the next morning started it up missing like crazy. Guess I will try wires next.

 

Or Coil?

 

^^Yup....wires and coil. Coil can be spendy($110 or so retail for mine)...if you've got a local guy with the same engine, I'd rather try out a known good coil before spending the money on something you don't need and that's non-returnable.