Jschobel

I have a 2006 F150 with the 5.4 trition and just changed the spark plugs and coil packs because the truck was missing real bad. After I had changed everything the truck has been idling really hard and dying at stop lights. It also threw a few codes and the check engine light came on. Also it says check fuel cap in the screen with the odometer. The codes say the truck is running lean. Can someone help me and tell if there is anyway to fix this without taking it to a shop.

dyeguy1212

iTrader: (1)

Did you disconnect the battery for a while and let it idle to relearn the air fuel mixture needed?

screamineagle

X2, disconnect the negative battery cable and turn on the headlights for 30 minutes or so and report back.

Jschobel

Yes I have done both of those and it is still idling hard and dying if it sits for a while at a stop light.

Summers22

iTrader: (2)

What brand of coil packs did you use?

Summers22

iTrader: (2)

Also you sure, 100% sure everything that you unplugged or moved is back where it belongs? Vacuum lines, electrical connections, etc...

homer

Agree on the vacuum lines, also not smelling any fuel in the engine compartment while running? I know there's an issue with people not torqueing the plugs enough and smelling raw fuel... I've never really heard that it would cause a lean condition though. A longshot but another thing to consider.


The fuel cap leads me more to a line being pulled off or something. Basically it's telling you the EGR system can't pressurize and the most common cause of that issue is people leaving the cap open. I'd have another look for any hoses sitting around.

techrep

iTrader: (1)

Umm.... replace you gas cap...bad seal will cause problems...

homer

If the cap doesn't do it.... tracing an EGR problem can be a real nightmare... in fact, cheaper to go to the dealer if you can't find a loose vacuum line or anything as they usually put it on a smoke machine. I'd be surprised if a bad cap makes it drive lean though personally. That system doesn't affect fuel pressure flow, it affects fuel vapour for burning (emissions). I know a few vehicles with the generic emissions code (gas cap - typically but not in these cases) and it's never affected driveability but it's annoying because it affects emissions (and will fail aircare in places like Vancouver). Worth a try though.