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TuningBot DTC Database · v4.37.14

P042C Catalyst Temperature Sensor Circuit Low Bank 1 Sensor 2

Generic (OBD-II) interpretation in the TuningBot DTC database.

P · PowertrainEmissionsOBD2

What P042C means

P042C
Catalyst Temperature Sensor Circuit Low Bank 1 Sensor 2 Generic · emissions Data confidence 85%

The control module detected that the signal in the Catalyst Temperature circuit stayed below the expected operating range.

Symptoms

  • MIL illuminated
  • Possible smell of unburnt fuel or reduced performance in severe cases

Possible causes

  • Aged or damaged catalytic converter
  • Downstream oxygen sensor fault giving a wrong efficiency reading
  • Exhaust leak
  • Misfire or mixture fault overloading the catalyst

Recommended checks

  • Compare upstream and downstream oxygen sensor signals
  • Check for exhaust leaks
  • Check for stored misfire or mixture codes first
  • Verify catalyst temperature plausibility where available

Related and nearby codes

How to read P042C

P

Powertrain: engine, transmission and driveline systems.

0

Generic SAE-standard code: same meaning on every make.

42C

Specific fault index within the subsystem.

Frequently asked questions about P042C

What does P042C mean?

Catalyst Temperature Sensor Circuit Low Bank 1 Sensor 2. The control module detected that the signal in the Catalyst Temperature circuit stayed below the expected operating range.

Is P042C generic or manufacturer-specific?

P042C is a generic OBD-II code: it has the same meaning on every make and model that follows the SAE standard.

Can TuningBot remove P042C at file level?

If the fault logic lives in the ECU calibration, yes: our DTC Removal file service disables the specific fault entry and, where the ECU needs it, corrects the checksum too. Not sure whether your case qualifies? Request a free assessment and our engineers will check your ECU file.

Other file services

ECU tuningDyno-tested results by model and engine See the results →

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