2000 Volkswagen Passat GLS 4 Cyl 1.8L
Transmissions & Drivetrains
Trouble codes P1116, P1136, P1565, P0140
Catalytic converter becomes red hot
In trying to give you a direction to go that will make a difference I make certain assumptions because I cannot know everything because I'm here and the car is there. However, in looking at the meaning of each of these codes I look for a common detail that may relate these codes to one another. Three of these codes are related to oxygen sensor circuit problems and one is related to either a vacuum leak or a bad mass air flow sensor. So without the car for me to do my own diagnostics, you stand a good chance of improving substantially the running (or actually fixing it) by replacing the mass air flow sensor (easy to replace) replace both the front and rear oxygen sensors and visually check each and every vacuum hose that could crack or leak vacuum. Pay attention to the Brake Booster Vacuum Supply Hose and any other vacuum lines at the intake manifold.