Applicable Systems
OBD-II
Symptoms
The catalyst system efficiency is below the required threshold. Emissions may exceed regulatory limits.
Possible Causes
- Catalytic converter degraded or contaminated
- Oxygen sensor readings inaccurate
- Engine running condition causing catalyst overload
Troubleshooting Steps
- Step 1: Compare pre- and post-catalyst O2 sensor readings
Readings indicate low catalyst efficiency - Step 2: Inspect catalytic converter for physical damage
Converter intact but degraded - Step 3: Check engine fuel trim and combustion efficiency
Fuel trim within specification
How to Reset
To reset: Clear the DTC after restoring catalyst efficiency to specification.
Source: SAE J2012 OBD-II Diagnostic Trouble Codes, SAE International
Category: OBD-II