P042A

Catalyst Temperature Sensor Circuit Bank 1 Sensor 2

Severity

⚠️ Medium

Can you drive?

Limited driving only, diagnose soon

Approx. repair cost

$56–167 (est.)

Symptoms

Check Engine light comes on
Reduced engine power
Increased fuel consumption
Unstable engine operation at idle

Causes

Malfunction of the catalytic converter temperature sensor
Open or short circuit in wiring harness
Poor contact in the sensor connector
Malfunction of the catalytic converter
Problems with the engine control unit (ECU)

How to Fix

Check the integrity of the wiring harness and sensor connector
Measure the resistance of the temperature sensor (compare with factory values)
Check the sensor signal using an oscilloscope or scanner
Replace temperature sensor if necessary
Check the condition of the catalytic converter

Related codes

P0420 P0430 P0135 P0141