P2423
PowertrainCatalystmoderate severityHC Adsorption Catalyst Efficiency Below Threshold (Bank 1)
What P2423 Means
The hydrocarbon adsorption catalyst on bank 1 is not trapping and converting HC emissions effectively. This usually means the catalyst has degraded over time.
Symptoms
- Check engine light on
- Failed emissions test
- Reduced catalyst performance
Common Causes
- Degraded or aged catalyst
- Exhaust leak upstream of catalyst
- Faulty oxygen sensor readings
- Engine running rich causing damage
Diagnostic Steps
- Scan and verify related codes
- Inspect exhaust system for leaks
- Check oxygen sensor operation
- Replace catalyst if efficiency low
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