From Ross-Tech Wiki
16816/P0432 - Main Catalyst: Bank 2: Efficiency Below Threshold
- MIL on
- Failed ceramic monolith in Catalyst
- Failed O2 sensors
- Leak in exhaust system
- Firmware issue with ECM
- Inspect cat for internal rattle, replace if needed.
- Perform Readiness test for Catalyst.
- Confirm pre and post O2 sensor are working to design.
- Confirm there are no exhaust leaks.
- Check ECM to see if there is a firmware update.
- For Audi engine codes ART or AKB, please see TSB 26-04-01
- For Audi engine code ATQ, please see TSB 26-08-07
- For Volkswagen engines, please see TSB 01-07-07
- As per TSB 01-07-54, do not replace the ECM for this DTC. Please see TSB for complete details.