2004 Ram 1500 5.7 hemi. Check engine light came on out of nowhere. Had only driven 1/2 mile or so. Had 1/4 tank of gas. Filled up and light went off until at 1/4 tank again days later. Any ideas without getting code checked? Gas cap maybe? Filling up again tomorow. Will see if it goes out again. Thanks

 

yeah might be a bad gas cap.

 

You're right maybe it's a gas cap!!!

 

i would say gas cap, but maybe your fuel lines have pin holes in them or are rotting. Seems like a loss of fuel pressure.

 

i have been having the same problem. almost every time i fill up my light comes on. it doesnt matter how far i tighten the cap when i get gas it comes on. i get out and tighten the cap a few more clicks and it goes away. im fixing to replace my cap. sounds like you are having the same issue.

 

Cap fo sho... lol

 

cap or leak in the evap system somewhere...

 

fo sho^^^^lol

 

Thanks guys. Just filled up and light went off. Will try cap and go from there. Hope it's that simple.

MED

 

try turning your key off and to the on position (where all the fans start up) 3 times and the check engine code should show up on the odometer display and there should be a thread somewhere on here about it. mine was doing similar things. topping off the tank can cause gas to leak down the evap lines and damage the canister. whenever my gas light would come on i would just put in 20 gallons instead of 28 or so it could hold and magically my light went out.