Catalyst Temperature Sensor Low (Bank 2)
The P0437 code means the vehicle's onboard diagnostic system has detected: Catalyst Temperature Sensor Low (Bank 2). This is a low severity code.
- Keep driving?
- Yes, but fix soon
- DIY difficulty
- moderate
- Estimated cost
- $80 - $300 (parts and labor)
Reads enhanced codes and shows real-time O2 sensor data. Verify the cat is actually bad before dropping $1,000+ on a replacement.
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Common Symptoms
- Check Engine Light illuminated
- No drivability symptoms
- Bank 2 catalyst temperature reads abnormally low
- Failed emissions test
Probable Causes (Ranked by Likelihood)
- Faulty Bank 2 catalyst temperature sensor Very High
- Open signal wire in Bank 2 sensor circuit High
- Corroded or loose Bank 2 sensor connector Moderate
- ECM Bank 2 input circuit fault Low
Step-by-Step Diagnostic Procedure
-
Check Bank 2 catalyst temperature on a scan tool -- should match ambient when cold and rise with engine operation
-
Inspect the Bank 2 sensor connector for corrosion
-
Measure signal wire voltage at the ECM connector for Bank 2
-
Check for open circuit in signal or ground wires
-
Replace the sensor if wiring is confirmed good and readings remain low
Frequently Asked Questions
Can I drive with code P0437?
Yes. The low temperature reading on Bank 2 does not affect engine operation or drivability.
Is P0437 the Bank 2 version of P0427?
Yes. P0427 indicates Bank 1 catalyst temperature sensor low and P0437 is the equivalent for Bank 2.
Could a large exhaust leak cause P0437?
Yes. A significant exhaust leak on Bank 2 before the sensor can introduce cool ambient air, causing lower temperature readings even if the sensor itself is functioning properly.
Sources
This page is built from documented references. Verify against your own service info before repair work.
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