A P0420 diagnostic code on your 2021 Ford Bronco indicates that Bank 1's catalytic converter efficiency has fallen below acceptable thresholds. The Bronco's off-road capability subjects exhaust systems to additional stress.
2021 Bronco Engine Options
- 2.3L EcoBoost 4-cylinder: 300 hp (single bank)
- 2.7L EcoBoost V6: 330 hp (dual bank)
The V6 has dual exhaust banks - P0420 affects Bank 1. The 4-cylinder has single bank.
Off-Road Considerations
Bronco converters face additional challenges:
- Trail Impacts: Rocks and obstacles
- Water Crossings: Thermal shock
- Vibration: Loosened connections
- Dust/Debris: Contamination
Common Causes
- Physical Damage: Off-road impacts
- O2 Sensor Issues: False codes
- Exhaust Leaks: Loosened by vibration