Subaru TSB #09-110-23
2021 Subaru Ascent
Affected Component: EQUIPMENT
- Summary
- This Service Information Bulletin announces diagnostic service procedures to be followed when DTC P0420 (Catalyst System Efficiency Below Threshold Bank 1) is detected by the Engine Control Module (ECM). If DTC P0420 is found to be stored in the ECM, follow the diagnostic procedures outlined below.