I have a 2000 Ford F150 4.2 6 cyl. supercab and about a month ago I got hit on the left side by a motorcycle close to the fuel cap. As of that moment after you go 40 mph or more,it begans to jerk and if I press hard on the gas I can hear something like an explosion coming out from the exhaust. Anybody have an idea what to do to fix this problem? Thanks.

 

Most likely there is a fuel vapor line blocked. Check for kinked lines going to the evap canister or the vent tube going from the filler neck to the tank. I would also venture to guess that the gas cap hisses and has alot of built up pressure within the fuel tank... right?