I recently took my '02 Jetta GLX, to a local mechanic because it had the 0420 error code which states there's an issue with the Catalyst, so the mechanic replaced the catalytic converter, now the car is feeling very sluggish and just not right in general. Could someone please let me know why? Did the wrong converter get put in? Or did something else happen? I'm taking the car back tomorrow to the mechanic, but if I could get some type of an idea as to what happened, I could tell him exactly what's wrong. Thanks in advanced.