Alright gents heres the problem,

So I've had my 04 5.4 screw since about 35000 miles. She has always had a loud engine knock and and loud Click about every 20 seconds, and from what I've read knocking on the 04 is pretty standard so I Brushed it off. Recently its seems to be running a little rough and today I stepped on it to pass a minivan and the truck began to struggle and jump trying to get speed up. It eventually got up to speed but still is not driving like normal.

I searched similar problems on the forum before posting and pieced together it might be the spark plugs. The truck is now at 67000 miles and to all my knowledge has not had the spark plugs changed.

Any help with this little problem would be greatly appreciated!

Specs - Truck is a 2004 5.4 running a PHP 87 performance tune with k&n filter, magnaflow, and 5w 20 Royal Purp.

Thanks again for the help!

 

Change the plugs, clean the MAF and throttle body, and throw the K&N away.

 

Thanks for chiming in glc! So I Cleaned the MAF and throttle body this afternoon, Spark plugs will most likely occur next week when I put in my 5100's. So why no love for the K&N, what do you suggest?

 

No love for a K&N - it doesn't filter anywhere near as well as a paper filter, and the oil can foul the MAF. I'm using an Amsoil filter in the stock air box, but any good name brand paper filter (Motorcraft, Wix, Purolator) is fine. You can do a Gotts/DWV mod to the stock airbox to help with airflow.