2003 jetta P0420 trouble code.....
 

back story: was driving the 2.0 down to visit family. The car was driving/idling fine. I got off the freeway and started driving in town. The engine shuddered a bit the died. I put it in park and started it up again. It started and I went on my way. I drove back home 300 miles away with no driveability problems. I hooked up my OBD ii and the only code was P0420. I found out vw will replace the cat up until 100K miles(8k away) but the nearest dealer is 4 hours away. I don't want to drive all that way if there is no prob with the cat. Any suggestions? My next step is testing the o2 sensors. I just don't know why it died like that but does not idle or run rough or anything.... Yet has this code. Thanks for the help in advance, I seriously appreciate it.

code
 

Hi, I think you need a tool can read the code, and a tool can test it, and diagnostic it.