have an 01 f150 5.7 v8 super crew 92,000 miles. ignition coil went bad and replaced, truck ran great for 1 week, then 2 more went bad. took it in to replace the 2 and change the plugs. also had injection clean. they used autolite platinums for the plugs. truck idles fine no check engine light but when warmed up acceleration gets bad with slight engine knock. saw the thread on egr ports and throttle body cleaning, which certainly should be done, but just not sure thats my problem. as i said everything was great until last 2 coils went bad, after tune up it runs worse. thoughts?

 

Get motorcraft plugs! Those autolites will cause you problems.

 

ya think? wondered bout that but wasnt asked what plugs to use. already paid once to get it done. that could be the cause?

 

Definitely. You wouldn't be the first to have problems like this pop up right after changing the plugs. Also make sure they are torqued down to 28/ft lbs or they will fly out of the heads and cost you more money.

I wonder if the knocking you are hearing couldn't be the plugs moving a little bit in the head.

 

sounds more like valves knocking. use motorcraft platinums...double..triple??