I have a 2001 F-150 truck with a 5.4L engine that after parking in the garage one night started up running rough and when driving down the road was missing and was shaking really bad in the speed of 40-52mph then smoothed out when I backed off the gas to maintain 55mph. The service engine light light has now come on 2 days later. Also before parking the truck in the garage the low fuel light did come on for about 1 mile. I have since added fuel injector clener, and changed the fuel filter and then added a gas line drier for what looked like water in the filter and line. My truck now idles rough mainly when the drive selector is put in a gear. The engine sound fine in park and neutral. Please help?

 

the very first thing you have to do is to take the truck to advance/discount, and they will read the codes for you for free that are causing the check engine light to come on. they will tell you and give you a print out. post those codes here so we can be of further help to you.

 

could be the common weak cop's causing a "low grade" misfire.

 

On the way to advance auto parts the trucks finally stopped missing. I still went to the store and had the truck read for error codes and the only code that came up was [P0307 cylinder 7 misfire detected]. After talking to the guys at the counter they said it could be the plug or the coil or maybe the injector was just dirty and is now finally working. I didn't buy any parts yet, I think I am going to wait to see if the SES light comes on again or the truck misfires before buying any parts. Does anyone agree and is it safe for the engine?