2005 f150
4.6 v8
43,000 miles
Truck was running ok but throttle body was dirty so I cleaned it. I had the battery disconnected. Put everything back, truck hunts and misses and poor idle. Did a battery relearn 2 weeks ago and while I don't drive the truck much I would estimate close to 100 miles driven. CEL reports p0301 and p1000. Misfire on cylinder one. Replaced cop and fuel injector. Cleaned MAF. New fuel filter. New pcv. Once in a while I can start the truck and it runs fine but as soon as you shut it off and restart it, it will have a weird miss with no pattern. Put in drive or reverse the truck shudders for several seconds to minute then will run fine even under heavy throttle. Drove over an hour on the interstate no problems, shut it off, right back.
I have searched extensively and am at a complete loss.

 

Spark plugs?

 

I had that in the back of my mind but with only 43,000 and it was running fine before I cleaned the throttle body?
I thought I might pull #1 plug and inspect it but I hate to touch any plugs lol

 

Check into it. There was a lawsuit because of the 5.4 triton engines. As far as I know the 4.6 have the same issues. I don't know if the 4.6 are covered by the same lawsuit over the spark plugs but it's worth a look. I had a 2004 5.4 and a letter was received about it but I traded it before it was a problem.

 

From what I have gathered, the 2v motors only ejected their plugs and it is more prone on early model 5.4, lots of v10 and some early model 4.6. I just can't imagine that the plug was fine, cleaned the throttle body, plug went bad.

 

Im starting to wonder if its possible that the relearn procedure still has not completed causing a slightly leaned out trim that is starving cylinder 1 since its furthest from the tank.
idk i guess im going to pull that plug and if thats not the culprit im probably going to drop it at the shop......