I have an 02 Ford F-150 5.4l. I spent all day yesterday driving to a regular mechanic who then sent me to a transmission shop who then sent me to a muffler shop. Now my truck is at my original mechanic and he is stumped. I all of a sudden lost power in my truck. Started out just mainly on hills but now more often. Muffler shop said cats are working. Changed mass air flow sensor and pigtail. Checked fuel pressure. Everything normal. Checked hose going from pcv valve was fine. Only thing that was done different was when I got my oil changed they accidentally used 530 instead of my usual 520. Please help

 

Drain that oil and use motorcraft 5-20 semi synthetic. Sounds like a stuck phaser to me.

 

You see I thought about that as it started messing up right after my oil change. Was told it was just a coincidence and that the oil weight used wasn't different enough to cause problems. But before this I did my own oil changes and used ford 520 synthetic blend oil and the motorcraft filter

 

Would that throw a check engine light or no? Because I haven't had it come on