Check for any exhaust leaks. Towing something behind you with an exhaust leak keeps the hot air stuffed up under the truck, which boils the fuel in the tank. Top of the muffler is a common place for leaks, because it's so hard to see rust there.Hey, all, reading through this thread again and having issues with my 07.
New gas cap and charcoal canister. Zero pressure at cap.
No issues at all on a daily basis.
Just bought a camper and towing it over hills brought back the gas fumes. Ethanol-free gas and it disappears.
270k miles, built truck, but towing well within my limits at 3500 lbs and a few years ago hauling my horse never had this problem.
Any ideas? Just stick with non-ethanol when I'm pushing the engine?