Catalyst Temperature Sensor
Reports converter temperature so the module can protect the substrate and grade its warm-up behaviour — an over-temperature reading can trigger a fuelling change or a power reduction before damage occurs. It sits directly in exhaust heat and its harness suffers more than most, so the wiring along the exhaust deserves inspection before the sensor is replaced. A genuinely high reading is worth taking seriously rather than dismissing as a sensor fault: a misfire or rich mixture really can overheat a converter to destruction.
Also known as: cat temp sensor, catalyst temp sensor, converter temperature sensor
Referenced by 20 codes
Codes involving this component (20)
- P0424 Heated Catalyst Temperature Below Threshold — Bank 1 Moderate
- P0434 Heated Catalyst Temperature Below Threshold — Bank 2 Moderate
- P0425 Catalyst Temperature Sensor Circuit Bank 1 Sensor 1 Low
- P0426 Catalyst Temperature Sensor Circuit Range/Performance Bank 1 Sensor 1 Low
- P0427 Catalyst Temperature Sensor Circuit Low Bank 1 Sensor 1 Low
- P0428 Catalyst Temperature Sensor Circuit High Bank 1 Sensor 1 Low
- P042A Catalyst Temperature Sensor Circuit Bank 1 Sensor 2
- P042B Catalyst Temperature Sensor Circuit Range/Performance Bank 1 Sensor 2
- P042C Catalyst Temperature Sensor Circuit Low Bank 1 Sensor 2
- P042D Catalyst Temperature Sensor Circuit High Bank 1 Sensor 2
- P0435 Catalyst Temperature Sensor Circuit Bank 2 Sensor 1 Low
- P0436 Catalyst Temperature Sensor Circuit Range/Performance Bank 2 Sensor 1 Low
- P0437 Catalyst Temperature Sensor Circuit Low Bank 2 Sensor 1 Low
- P0438 Catalyst Temperature Sensor Circuit High Bank 2 Sensor 1 Low
- P043A Catalyst Temperature Sensor Circuit Bank 2 Sensor 2
- P043B Catalyst Temperature Sensor Circuit Range/Performance Bank 2 Sensor 2
- P043C Catalyst Temperature Sensor Circuit Low Bank 2 Sensor 2
- P043D Catalyst Temperature Sensor Circuit High Bank 2 Sensor 2
- P046A Catalyst Temperature Sensor 1/2 Correlation Bank 1
- P046B Catalyst Temperature Sensor 1/2 Correlation Bank 2
Other components in Exhaust and Emissions
- Oxygen Sensor 326
- EGR Valve 150
- Catalytic Converter 142
- NOx Sensor 118
- Reductant Injector 107
- Exhaust Gas Temperature Sensor 95
- Reductant Tank 95
- Diesel Particulate Filter 76
- SCR Catalyst 65
- EGR Cooler 62
- Exhaust Gas Differential Pressure Sensor 58
- Fuel Tank Pressure Sensor 58
- Exhaust Pressure Control Valve 56
- Reductant Heater 55
- Reductant Pump 51
- EVAP Vent Valve 43
- Exhaust Aftertreatment Fuel Injector 42
- Charcoal Canister 33
- EGR Position Sensor 32
- Secondary Air Injection Pump 32
- Reductant Temperature Sensor 29
- EVAP Leak Detection Pump 29
- EVAP Purge Valve 27
- Particulate Matter Sensor 24
- Reductant Control Module 24
- Reductant Level Sensor 23
- Secondary Air Switching Valve 22
- EGR Temperature Sensor 21
- Secondary Air Check Valve 21
- Catalyst Heater 20
- Fuel Filler Cap 18
- EGR Cooler Bypass Valve 16
- Reductant Quality Sensor 16
- Exhaust Back Pressure Sensor 15
- Purge Flow Sensor 13
- Direct Ozone Reduction Catalyst 13
- EGR Vacuum Solenoid 9
- Fuel Vapour Temperature Sensor 5
- Fuel Additive Control Module 4
- Fuel Additive Tank 4
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Working on this component
Be the first to write this up
Nothing posted about this yet. Whatever you found is worth writing down — even a dead end saves someone the same afternoon.
What makes one worth reading:
- The car — make, model, year and engine. The same fault behaves differently on each.
- What you measured, not only what you replaced.
- What actually fixed it — or that nothing did, which is worth knowing too.
Sign in or create an account to add what you found about Catalyst Temperature Sensor.