Hey All I Got a 2004 F250 Lariat 4Dr Crew Cab Long Bed with he 5.4 in it, I did half a tune up on the truck today before day light ran out, I Replaced all the plugs on the Passenger side will do the drivers side tmrw, but when I started it after the plugs were done the idle was a little rough (not stalling out rough) you can feel it has a little shake to it, I've been reading that the pcv may be bad ? I got the truck scanned at auto zone and it was a p071 code and something else, i checked to make sure I didn't break anything ended up finding nothing wrong, I'm kinda lost. Does this sound like a PCV issue ?

 

What did you install for spark plugs?

 

did you put dielectric grease on the plug cap ???

I would suspect one of the Coil over plugs

 

I used oem motor craft plugs, wouldn't throw a misfire code if the coil was bad

 

Did you check the gaps on the plugs before you put them in?

 

I did use grease on the plugs

 

Was the code P0171?
If the "something else" was P0174 you probably have a large vacuum leak.
Check the PCV vacuum hose where it connects to the throttle body.
You can get a basic code reader at Amazon for $13 - OBD2 Code Reader - MS300.

 

yea its 171 and 174 I did check the gap its at 55

 

I would finish changing your plugs before I started throwing money at error codes.

 

I would fix whatever was knocked loose and is causing the vacuum leak before driving it.

 

Heres an update, Replaced the PCV valve and replaced the Mass Air Flow and everything seems to be ok drove 100 miles today and the Check Engine Light Did not come back on, The Perks of working for a auto parts store is I have parts at my disposal lol I'll finish the other 4 plugs tmrw

 

the real question "IS" did you learn "WHAT" caused the problem. ?????????

throwing parts does not equal learning to repair..

my opinion.