Check engine light came on, dealer read the code and determined the catalytic converter was bad and had to be replaced. Their cost to replace was in the neighborhood of $1,400 I argued that it should not have gone bad so quickly and that the part must be defective, but you can't argue with the dealer. Car was past the warranty mileage. I found the part online for a little under $400 and replaced it in my driveway. Some months later I recieved a recall notification for this very same problem and VW would replace the part for free or reimburse you if you had the part replaced ...by a mechanic/shop. Since I did it myself, I got nothing from VW.

My Beetle now has 247,000+ miles and I've had to make this repair one other time, probably at around 190,000 miles. During that replacement, 3 of 6 manifold bolts snapped and had to be drilled out and replaced. One was impossible to properly drill out so (because I needed the car) I used a small bit and replacement bolt; as a result, I now have an exhaust leak at the manifold.

Because the Cat is welded to the downpipe, replacing the Catalytic converter is NOT an easy job - at least not in one's driveway; might be easier with a lift(?).