I have a 2003 F-150 5.4 Triton FX4. As of about a month ago it began jerking when i would go up hills and during light acceleration. The local auto parts store suggested that i replace the EGR valve and DPFE Sensor, but the problem has worsened. No check engine light so no codes. Also i am showing a warning notifying me that my gas cap is loose, but it's not. Anything?

 

You can have codes without check engine light coming on. Check plugs for sure, one may lose and fixing to blow out, and also unplug one coil at a time and see if it effects the idle. If the idle doesn't change when unplugging one, good chance the cop is bad. Just went threw this on mine. Have a parts house ready your puter and look for yourself to see what they may be and write them down and then come back and post.

 

Exactly what is telling you that the gas cap is loose?

You may be due for new spark plugs and/or coils.

 

I will definitely check the coils and plugs.

There is a warning light to the far right of the guages that shows an unscrewed gas cap. I've replaced the cap twice and the light keeps coming back.