Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2021 Lexus RX 450hLFACTORY OEM SERVICE PROCEDURE
Engine Control System (Diagnostic Codes) (5 Of 8)
- SFI System
- DTC P0420: Catalyst System Efficiency Below Threshold (Bank 1); DTC P0430: Catalyst System Efficiency Below Threshold (Bank 2) [10/2015 - 07/2020]
- DTC P0420: Catalyst System Efficiency Below Threshold (Bank 1); DTC P0430: Catalyst System Efficiency Below Threshold (Bank 2) [07/2020 - ]
- DTC P043E: Evaporative Emission System Leak Detection Reference Orifice Low Flow; DTC P043F: Evaporative Emission System Leak Detection Reference Orifice High Flow; DTC P2401: Evaporative Emission Leak Detection Pump Stuck OFF; DTC P2402: Evaporative Emission Leak Detection Pump Stuck ON; DTC P2419: Evaporative Emission Pressure Switching Valve Stuck ON [10/2015 - ]
- DTC P0441: Evaporative Emission Control System Incorrect Purge Flow [10/2015 - ]
- DTC P0451: Evaporative Emission Control System Pressure Sensor Range / Performance; DTC P0452: Evaporative Emission Control System Pressure Sensor / Switch Low Input; DTC P0453: Evaporative Emission Control System Pressure Sensor / Switch High Input [10/2015 - 08/2018]
- DTC P0451: Evaporative Emission Control System Pressure Sensor Range / Performance; DTC P0452: Evaporative Emission Control System Pressure Sensor / Switch Low Input; DTC P0453: Evaporative Emission Control System Pressure Sensor / Switch High Input [08/2018 - ]
- DTC P0505: Idle Control System [10/2015 - 07/2020]
- DTC P0505: Idle Control System [07/2020 - ]
- DTC P050A: Cold Start Idle Air Control System Performance [10/2015 - 12/2017]
- DTC P050A: Cold Start Idle Air Control System Performance [12/2017 - 07/2020]
- DTC P050A: Cold Start Idle Air Control System Performance [07/2020 - ]
- DTC P050B: Cold Start Ignition Timing Performance [10/2015 - 12/2017]
- DTC P050B: Cold Start Ignition Timing Performance [12/2017 - 07/2020]
- DTC P050B: Cold Start Ignition Timing Performance [07/2020 - ]
Factory Service Tools
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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