P042C
Catalyst Temperature Sensor Circuit Low
Catalyst temperature sensor at bank 1 sensor 2 below lower plausibility — short to ground. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.
Catalyst temperature sensor at bank 1 sensor 2 below lower plausibility — short to ground. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.
Common causes
- high
Short to ground
One of the most commonly reported causes for this code — check this first.
Typical part cost: $70-550
- low
Connector pins corroded - high contact resistance
Less common, but worth ruling out after the more likely causes.
Typical part cost: $70-550
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First things to check
- 1Confirm the code with a scan tool and check for additional related codes.
- 2Inspect the relevant sensors, wiring, and connectors for damage or corrosion.
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Related codes
See related trouble codes
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Frequently asked questions
What does P042C mean?
P042C means "Catalyst Temperature Sensor Circuit Low (Bank 1 Sensor 2)". It is a generic OBD-II code that points to a fault in the auxiliary emission controls.
What are the most common causes of P042C?
short to ground; connector pins corroded - high contact resistance; harness chafing through insulation — these are the most commonly reported causes. Verify with a proper diagnosis before replacing parts, or use the Wrenchify app for a vehicle-specific diagnosis.
Can I keep driving with this code?
The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical. Use the Wrenchify app for a full diagnosis specific to your vehicle.
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