My brother has a 2004 F150 4.6. He's getting the following codes. P0300, P0304, P0305, P0397, P0316, P0354

Any idea what is causing all of the misfires? Does he have 3 bad COPs?

 

Would a dirty Fuel filter cause this?

 

He didn't by chance power wash the motor or drive though a lake?
Or....
Has crappy wanna be performance plugs installed other than motocraft NGK Denso.

 

I'll ask He had the plugs changed about 1 year ago.

 

We changed COP #4. Still have the same codes. Running a little better though.

Any ideas?

 

Just had the same problems with 2007 5.4 both cats melted. It was a bad day

 

Personally if you've got money to throw at the problem.....
Start with a fresh set of motorcraft plugs and a set of cops......
The cops can be found on eBay at uneek or global......

 

Sounds like it.......

 

If you don't have money to throw at it, clear codes, move three suspect cops to other plugs and see if the codes come back on the old cylinders (plugs) or new locations (coils).

Did he change boots when he changed plugs?