Alright this is becoming very annoying for me now. I need help with diagnosing this problem I am having. Everytime I use my a/c without using the recirculate button I get the smell of exhaust and or gas coming through the vents. Can anyone tell me what the issue is that I am dealing with. A side note: I also smell exhaust underneath the driverside when ever the vehicle is warmed up. All filters, important sensors, spark plugs and wires as well as a new cat. converter replaced. Any ideas will be appreciated. By the way this is on a 04 TB LT I6 4x4, non EXT.