when i was driving home on the free way my emission system warning light came on and as i stoped at the light i noticed my rpms would not stay at a constant level, my truck is not running very smooth it jerks as im stopped but goes away when i get up to speed i cant get it to the mechanic till tuesday, any ideas on whats going on? oh and its a 2007 5.4L F-150


i did a little mudding earlier that morning could that have caused this?

 

Do you mean check engine light? Go to your local parts store like autozone and have them pull your codes for free. Post codes here and someone should be able to help. Don't let them sell you anything after they pull the codes.

 

yeah it looks likes the classic check engine light but i looked it up in the ford manuel and it says its the emissions systeam but thinks ill be sure to take it there in the morning