Rough Idle after Changing 4 spark plugs

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Oct 18, 2017 | 11:40 PM

Spartan250

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Rough Idle after Changing 4 spark plugs

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 ?

Oct 19, 2017 | 06:31 AM

projectSHO89

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From: St Louis

What did you install for spark plugs?

Oct 19, 2017 | 06:50 AM

speakerfritz

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

I would suspect one of the Coil over plugs

Oct 19, 2017 | 09:06 AM

Spartan250

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

Oct 19, 2017 | 09:08 AM

andym

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From: Bonita Springs FL

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

Oct 19, 2017 | 09:11 AM

Spartan250

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I did use grease on the plugs

Oct 19, 2017 | 11:39 AM

R&T Babich

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From: Thousand Oaks, CA

Quote:

Originally Posted by Spartan250

Hey All I Got a 2004 F250 Lariat 4Dr Crew Cab Long Bed with he 5.4 in it, ... I got the truck scanned at auto zone and it was a p071 code and something else, ...

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.

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Oct 19, 2017 | 02:51 PM

redford

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

Oct 19, 2017 | 03:39 PM

#10

projectSHO89

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From: St Louis

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

Oct 19, 2017 | 11:23 PM

#11

Spartan250

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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