P0420 Volkswagen -

Question

I have this code in my Volkswagen Jetta 2006, I replace in two time the catalytic, and the first time the check engine light appear at 200 miles, and the second time appear at 10 miles, I do not known wait.

Answer 1

P0420 Catalyst system below threshold

Is there any misfire code stored. Misfire can easily deteriate the catalytic convertor and so could a overfilled engine oil condition do the same. What can also set a catalytic code are exhaust leak prior to the the catalytic convertor. This particular vehicle are very prone to misfire conditions, where the ignition has been recalled for a misfire  condition .