A P0420 diagnostic code on your 2023 Ford Mustang indicates that Bank 1's catalytic converter efficiency has dropped below acceptable thresholds. The 2023 Mustang continues the S550 generation with proven powertrains.
2023 Mustang Engine Options
- 2.3L EcoBoost: 310 hp (single bank)
- 5.0L V8 GT: 450 hp (dual bank)
- 5.0L V8 Mach 1: 480 hp (dual bank)
V8 models have dual exhaust banks - P0420 affects Bank 1. EcoBoost has single bank.
P0420 on Newer Vehicle
A 2023 Mustang showing P0420 is relatively early for converter failure:
- O2 Sensor Issues: More likely than converter failure
- Performance Use: Can accelerate wear
- Modifications: May affect readings
Warranty Note
A 2023 Mustang should be under warranty (unmodified).