Hey all, I have a 99 F150 with a 4.6, last month I was getting a cylander 3 misfire code, I replaced the plugs, wires and coil packs, the truck had 124,000 miles on it. yesterday I noticed a miss again. I scanned the truck and it came up with a cylander 7 misfire. what should I check next? do you think I might have a bad plug? the ones I took out when I changed them looked normal. just a little fustrated...

Thanks

 

i ran some injector cleaner after i had felt my truck miss and changed gas stations, it seemed to help after a tank-ish... could be a some bad fuel, i was using exxon fuel and it would miss really bad and then i changed to shell and it lessened up to a rarity. now it only does it when its trying to run in OD at 40mph.
injector cleaner seems to help a fair bit too for what it is.

just some of what i did, maybe you could try something like that too? never know when your getting bad fuel anymore.

 

Fuel filter!

 

Replaced the filter 1000 miles ago, gonna fill it up at a different station.
and run some techron through it.. see what happens.

 

Hey I had a similiar problem with mine you could really feel it missing and it would shake under load. I changed the plugs and stuff also, turned out to be a plugged fuel injector. It was replaced it ran all good after that no problems.

Greg