P0434 OBD-II: Heated Catalyst Temperature Below Threshold

What Does P0434 Code Mean?

OBD-II Code P0434 is defined as a Heated Catalyst Temperature Below Threshold

The Catalytic Converter takes the exhaust gases left over by the combustion process and converts those gases to harmless emissions. The engine control module (PCM) compares the front and rear oxygen sensors to each other to determine catalytic converter efficiency. If the input from the rear oxygen sensor starts to match the front oxygen sensor, the PCM will set code P0434.Catalytic converters are covered under federally mandated 8yr/80,000 mile warranty by the vehicle's manufacturer. Catalytic converters usually fail as a result of something else (engine misfire, internal oil leak, or internal coolant leak) not being repaired. The original cause of the failure is usually not covered under warranty.

P0434 Symptoms

• Decreased engine performance

Common Problems That Trigger the P0434 Code

• Catalytic converter failure
• Oxygen sensor failure

Common Repairs Needed for the P0434 Code

• Oxygen Sensor Replacement
• Spark Plug Replacement
• Catalytic Converter Replacement