Not a F-150 but wifes 96 Explorer instead... Engine light has been on for 3 years since we bought it. It went off for a little while after we replaced the transmission... Tried the normal tune ups. etc. It runs fine gas mileage is normal to excellent but this light is annoying me... So I went to the auto store and borrowed thier scanner... Came up with a P404 (I think I forgot to write it down) Scan tool says "Exhaust recirculation error". What.. is.. this? Cats. or O2 sensor maybe?

Edited to add:
I cleared the codes then took the Explorer back across town to my wifes work and the light stayed off. I would just like to know what to look at if it comes back on otherwise I'm pulling the dang bulb out...

 

I'm guessing you mean P0404 or P1404 not P404, either way there is no such code. Try pulling the code again.

 

Since I cleared it it shouldnt be stored anymore should it? Hopefully it stays off but if it does not, then I will pull it again and write it down this time...