Don't buy the cheap aftermarket COPs replace with Motorcraft (Rock Auto).

I have three 5.4s (two are mine and my son has one) and they have been very good trucks, one has over 400k and another around approaching 300k with no issues other the routine maintenance like COPs.

I don't believe the issue is with the corrosion between metals because I've never had this issue with any of mine (97, 2001, & 2003) but they don't have the protruding plugs. I believe the issue is the carbon buildup on the part of the plug that protrudes past the threaded opening for the plug. It builds up and is bigger than the opening and won't back out. Run real heavy dose of carbon cleaner through your tank before changing the plugs and then crack each one if possible and pour some carbon cleaner in each one and let it seep in overnight and then back them out.

The only way you should have a problem with the threads seizing up is if someone has previously changed them without using anti-seize on the threads.

I believe u are correct gator.

I’ve decided I’m just gone bite the bullet this time and pay the ford dealership, I don’t want the headache and it’ll save me several bad words too.

I purchased on 06 with the 5.4 a few months ago. It has a little over 130k on it and the previous owner already had the plugs replaced. My truck had no CIL on but it idle and ran a little rough with a noticeable tick. After a little investigating and research I discovered I had (2) loose plugs. Re tightened them and now it's quiet at a church mouse, smooth idle and the power is back.

Pay someone, I got one and you'll probably need coils too.

Must have. I got 130000 out of one I had. Loved the truck just not the motor. LoL

Quote from ford dealership today was 912$ for plug replacement and cht sensor pigtail (which requires pulling the intake of all things). This motor is a nightmare to work on for sure. I may get it running and just sell it before something else happens.