Fault Code P0420

VWJettaGuy
Posts: 10
Joined: Fri Jan 22, 2016 6:59 am

Fault Code P0420

Post by VWJettaGuy » Fri Jun 16, 2017 6:57 am

This year the check engine light comes one. ODBC scanner reports 'P0420 Catalyst System Efficiency Below Threshold Bank 1'. Cleared code several times and returns a few weeks later. Used Chevron Techron Complete Fuel System Cleaner and no check engine for at least 3 months. Check engine light reappeared this week and same fault code. Next step is clean MAF and throttle body before considering a costly catalytic converter replacement.

04 VW Jetta GLS
2.0L L4 SOHC 20V
WAGON 4-DR
Engine Code BEV