Baffeled at what would cause this. happed on my way home last night, truck just started missing horribly, i parked it for the night, got up and took it to the part store, it ran fine the whole way there. when i ran the codes and got a cyl 7 misfire and bank 2 lean condition. after i cleared them it started running horrible again.

here lately ive noticed that ive been smelling what may be a cat getting hot and was wondering if this is what would cause the lean condition.

 

the cyl 7 misfire is what is causing the lean condition. If I had to take a stab at it, the misfire is letting raw unburned fuel into the exhaust/catalytic converter, possibly burning up in there and/or being let out through the tailpipes.

First thing I would do is take out the cyl7 COP/plugwire and make sure there is no coolant/oil/anything in the spark plug well. If there is, it is likely the cause of the misfire, and needs to be clean out 100%. If there isn't anything in there, then I'd move up the chain and inspect the spark system (spark plugs/coils/boots/plug wires).

 

well i suspect theres water there. i was playing pretty hard in the mud right before it started acting up. ill pull it and check it tomorrow if i can get to it. these expeditions arent the most fun vehicles to get to the back pasenger side of the motor. now my next question is why isnt it consistant? if the truck sits i can fire it up and drive it no problem, but once its warm it begins to miss again

 

well I don't think we can begin to hypothesize why it's not consistent if we don't know for sure what the problem is.

 

My truck had the same symptoms, it would run fine until it got warm and then ran like crap. I got codes for cyl four misfiring and running lean. Turned out to be the coil, plug and boot for number four. Replaced them and the problem and code have disappeared. I would bet money your problem is the coil, boot and plug. Mine had coolant in the well and the boot was split open, the plug electrode was almost gone and I'm not sure about the coil, I just replaced it anyways since I was there ($42 for the coil which comes with the boot and about $3 for the plug).

 

sorry its taken me so long to get back, but as it turns out it was the coil. when i pulled it there was a little water down in the plug valley and the boot was saturated. i blew the hole out pretty good and fought like hell putting the new coil in and now the truck runs fine!