Auto Parts: VW Jetta 2000, oxygen sensors, oxygen sensor

Question
My oxygen sensor is bad, where is it and how do i change it???

Answer
    It is located in the exhaust pipe.  Sometimes it is screwed directly into the manifold.  On a VW, this is easily visible between the engine and the radiator.  The oxygen sensor looks like a metal covered spark plug and has a wire or several wires in a harness attached to it.  Now, there may be a second oxygen sensor in the pipe behind the catalytic converter, but it is there to make sure that the first one is working.  If you've got a code that says the sensor is bad, it will be the one you can see in the front of the engine.  You will have to buy a special socket for removing oxygen sensors, which has a slot cut in it for the wires.  Just unscrew it (it will be tight, you will need a 1/2" drive ratchet or breaker bar), and screw the new one in.  The new one should have some anti-seize compound on the threads (silver paste), if it doesn't then get some and put it on, otherwise you will never get it out if you have to change it again.  While you're at it, make sure that the wires connect to it are OK.