Originally Posted by C4king
I have a 91 5.0 mustang, dose anyone know what type of gas cap they used on the 91 5.0 is it a vented one? Or non vented? I have been getting alot of pressure in my tank.. The other night my car started to run bad like it wasn't getting fuel or to much fuel.. I got out and unscrewed the cap and I had alot of pressure vent out, once I did that my car started running better..thanks for any and all help..
It should vent to the carbon canister on the passenger side of the engine compartment down low on the frame.
Maybe your vent line is kinked or stopped up?