MCrab

Replaced cam phasers, coil packs, and plugs on my 2004 FX4 with the 5.4. Now it seems like it takes forever to rev and get moving. The engine is running and idling smooth. No idiot lights or codes retrieved. Any ideas?

MCrab

Well, 85 have viewed with no responses. I will start with the basics. MAF, cleanand relearn the throttle body and fuel filter.

JCR 56

Might want to have the cats checked to make sure exhaust isn't restricted.

MCrab

Ahhh, now that you mention it, my exhaust note has changed somewhat. Wouldn't I get a light from that?

JCR 56

Well, maybe or maybe not, but to be on the safe side I would get it checked any way. You know the truck is not running worth a damn, light or not.

MCrab

Falls on its face after 2500-3000 RPM.

rsylvstr

Update??

Spanky666

My Ford has 230k miles on it. 98 F150 4.6L. I just had to replace all 4 cats myself. The cause of the problem was the valve stem seals had gone bad and it was sucking oil into the combustion chamber.

Changed those out, replaced the cats, ran some cleaner through the gas tank. Runs like a dream again