Bri4321Mil

2001 F-150 5.4 ...it starts and idles good when cold but when warmed up it looses power and sounds like it's not firing on all cylinders...112,000 miles and I'm pretty sure it's running on the original plugs...does this sound like a plug issue?

JCR 56

At 112,000 miles it's due a plug change, and I would use Motorcraft plugs.

Bri4321Mil

Yeah I need to change them anyway, but does this sound like a spark plug issue or something else?

Bri4321Mil

Also, should I change the COP's while I'm at it?

JCR 56

Hard to say, but I would change the plugs first. Any codes?

Bri4321Mil

No codes

grizzstang

Then buy a boot/spring kit for your COP's and reuse them. They are fairly expensive so I would see if plugs fix your issues first.

Bri4321Mil

So I'm in the process of changing the spark plugs, and the ones I'm pulling out are autolite plugs...are these original plugs?

akdoggie

No. Motorcraft is original.

Bri4321Mil

That's what I thought. I'm gonna go ahead and replace them with motorcraft though