Error code
OBD2 P0422
OBD2P0422
Diagnostic Trouble Code· Standard OBD-II fault code read from the vehicle's onboard diagnostics.
What it means
Main Catalyst Efficiency Below Threshold.
Severity
moderateCan drive, but efficiency and emissions will be compromised.
Summary
P0422 indicates that the main catalytic converter on bank 1 is not functioning efficiently enough to meet emission standards.
Symptoms
- Check engine light is on
- Decreased fuel efficiency
Common Causes
- Failing catalytic converter due to high mileage or contamination
- Faulty oxygen sensor(s) and/or wiring issues
- Engine thermostat not maintaining proper operating temperature
Diagnosis
- Check the temperature difference between input and output of the catalytic converter
- Inspect oxygen sensors for faults or wiring issues
- Ensure engine thermostat is functioning correctly
Fixes
- Replace faulty catalytic converter
FAQ
What does P0422 mean?
It indicates that the main catalytic converter on bank 1 is not working efficiently enough.
How do I diagnose P0422?
Measure temperature difference across the catalytic converter and check oxygen sensors for faults.
Not affiliated with OBD2. Answer summarized from the manufacturer's manual linked above; consult that source for the authoritative procedure.
More OBD2 codes
- P0400Exhaust Gas Recirculation Flow
- P0401Exhaust Gas Recirculation Flow Insufficient Detected
- P0402Exhaust Gas Recirculation Flow Excessive Detected
- P0403Exhaust Gas Recirculation Control Circuit
- P0404Exhaust Gas Recirculation Control Circuit Range/Performance
- P0405Exhaust Gas Recirculation Sensor 'A' Circuit Low
- P0406Exhaust Gas Recirculation Sensor 'A' Circuit High
- P0407Exhaust Gas Recirculation Sensor 'B' Circuit Low
- P0408Exhaust Gas Recirculation Sensor 'B' Circuit High
- P0409Exhaust Gas Recirculation Sensor 'A' Circuit
- P0410Secondary Air Injection System
- P0411Secondary Air Injection System Incorrect Flow Detected