Catalyst Temperature Sensor Circuit High (Bank 2, Sensor 1)
The catalyst temperature sensor on Bank 2 is reporting a voltage signal that is higher than expected, indicating a circuit malfunction. This sensor monitors exhaust temperature after the catalytic converter to ensure proper emission control system operation.
What You Might Notice
- Check engine light illuminated
- Poor engine performance or hesitation
- Decreased fuel economy
- Increased exhaust emissions
- Rough idle or stumbling during acceleration
Most Common Causes
- 1
Faulty catalyst temperature sensor
The sensor itself has failed and is sending an abnormally high voltage signal to the PCM. This is the most common cause of this code.
- 2
Wiring or connector problems
Corroded, damaged, or loose wiring in the sensor circuit can cause high voltage readings. Check the harness connection at the sensor and PCM.
- 3
Engine running too hot
Excessive exhaust temperatures from lean fuel mixture, ignition timing problems, or cooling system issues can push the sensor reading above threshold.
- 4
PCM malfunction or programming issue
In rare cases, a faulty powertrain control module or outdated PCM software may incorrectly interpret normal sensor signals as high.
How to Diagnose It
- 1
Check Faulty catalyst temperature sensor — The sensor itself has failed and is sending an abnormally high voltage signal to the PCM. This is the most common cause of this code.
- 2
Check Wiring or connector problems — Corroded, damaged, or loose wiring in the sensor circuit can cause high voltage readings. Check the harness connection at the sensor and PCM.
- 3
Check Engine running too hot — Excessive exhaust temperatures from lean fuel mixture, ignition timing problems, or cooling system issues can push the sensor reading above threshold.
- 4
Check PCM malfunction or programming issue — In rare cases, a faulty powertrain control module or outdated PCM software may incorrectly interpret normal sensor signals as high.
How to Fix It
- 1
Replace catalyst temperature sensor
Remove the faulty sensor from the exhaust system on Bank 2 and install a new OEM or quality aftermarket replacement. Apply anti-seize compound to the threads before installation.
- 2
Inspect and repair wiring harness
Check the sensor wiring for corrosion, cuts, or loose connections. Repair or replace damaged wiring and reconnect any loose connectors. Use dielectric grease on connections.
- 3
Diagnose and fix lean condition
Perform a comprehensive fuel system and ignition timing check. Address any issues causing the engine to run lean or hot, such as fuel injector problems or timing problems.
- 4
Update or reprogram PCM
Connect to dealer service to check for available PCM software updates. If an update is available, have it programmed into the module to resolve interpretation issues.
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