 Just look up the slew of problems with the 5.4L in this 2006. Apparently it has a lot of issues that Ford decided to hide from the public and failed to fix. There is a class action lawsuit on the spark plugs. Apparently, there are lots of other issues, including cam phase sensors. Mine started idling rough, wife drove it a couple of miles home, 2 hours later it was at the shop. The shop is about 1 mile away. Got the call today. It needs a new engine!!! Edit: We are now just waiting until the end of the year so we can donate it to charity. It's not even worth selling. Maybe I will get a small tax benefit out of it?