Ok, so the rear o2 sensor is the one behind the catalytic converter right? and the front one is the one on the manifold? Anyways, I just recently had the one the on the manifold replaced. I'm getting a check engine code for the catalytic converter which the shop told me the other o2 sensor is bad so I figure that is whats throwing the error(p0420). I can't find a solid "how to" video or anything for the car. I figure its easy. 2001 New Beetle 2.0 B. Thanks in advanced.