P0436

What it means

P0436 is the generic code for a range or performance fault in the catalyst temperature sensor circuit for Bank 2, Sensor 1. The control unit saw a signal from the sensor that was implausible compared with its expected value or with modelled exhaust temperature. It may be stuck, drifting, slow to respond or out of range. Where the sensor sits and what it is used for depends on the vehicle and engine.

Symptoms

• Engine warning light on
• Usually no change in driving, as the sensor is mainly monitoring
• Possible reduced power or limp mode on some vehicles if the temperature is used for component protection
• Possible failed emissions test or readiness monitors not completing
• Other catalyst or exhaust-related codes stored alongside

Possible causes

• Faulty or drifting catalyst temperature sensor on Bank 2likely
• Damaged, chafed or corroded wiring to the sensor, or a poor connectorlikely
• Exhaust leak near the sensor affecting the readingpossible
• Sensor contaminated or heat-damaged, for example from engine misfire or overly rich runningpossible
• Overheated or failing catalyst giving temperatures the control unit does not expectpossible
• Fault in the control unit or an outdated calibrationrare

How to diagnose

1. Read all stored and pending codes and the freeze frame data, and note any misfire, fuel trim or catalyst codes
2. Check that Bank 2 is correctly identified for this engine layout, and locate the sensor using model-specific information
3. Inspect the sensor, wiring and connector for damage, heat damage, water ingress, corrosion and chafing
4. Check for exhaust leaks around the sensor and upstream of it
5. Compare live catalyst temperature readings with the other bank and with the expected value as the engine warms up
6. Check the sensor circuit's supply, signal and earth, and its resistance, against the manufacturer's data
7. Check for misfire or fuelling faults that could overheat the catalyst or contaminate the sensor
8. Check for any applicable software updates or technical bulletins for the vehicle

How to fix

• Repair or replace damaged wiring, terminals or connectors
• Replace the Bank 2 catalyst temperature sensor if it is faulty or out of range
• Repair exhaust leaks affecting the sensor reading
• Fix any misfire or fuelling fault, then replace the catalyst if it is confirmed damaged
• Apply a manufacturer calibration update only if an outdated calibration is a known cause for this vehicle

Can I keep driving?

Nearby codes

• P0435GenericCatalyst Temperature Sensor Circuit Bank 2 Sensor 1
• P0437GenericCatalyst Temperature Sensor Circuit Low Bank 2 Sensor 1