I've owned a Ford with the 5.4. I had a 2001 F150 Lariat for 9 years.

The spark plug problem is real...but it is manageable. I lost three plugs at different times...they simply blew right out of the head...stripping the threads on the way out. The dealer told me the only solution was a new engine for $5,000. After a little research I found that there is indeed a much cheaper fix...it's called Time Sert threaded inserts. It's not cheap...but at $500 it's way cheaper than a new engine.

The plugs are a GIGANTIC pain in the rear-end to access. Call a local shop and ask them how much they charge to do a plug change on that vehicle...several years ago I was quoted $500 to change 8 plugs.

I've owned Chevy, Nissan, and Ford trucks...nobody makes a perfect one.

After driving that one for 9 years I bought another F150 because they are generally very good trucks...I think I just had some bad luck with mine. Like someone else mentioned above...have the price of a plug change subtracted from the purchase price, let a dealer do it, and I think you'll be real happy with it.