P2631 moderate

O2 Sensor Pumping Current Trim Circuit High Bank 2 Sensor 1

The P2631 code means the vehicle's onboard diagnostic system has detected: O2 Sensor Pumping Current Trim Circuit High Bank 2 Sensor 1. This is a moderate severity code.

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Keep driving?
Short distances only
DIY difficulty
moderate
Estimated cost
$150 - $500 (parts and labor)
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Common Symptoms

  • Bank 2 running lean
  • Hesitation from bank 2 cylinders
  • Higher exhaust temperatures on bank 2
  • Check engine light on

Probable Causes (Ranked by Likelihood)

  • Bank 2 wideband O2 sensor degraded Very High
  • Short to voltage in bank 2 sensor circuit High
  • Bank 2 sensor contaminated by coolant Moderate
  • ECM bank 2 driver stuck high Low

Step-by-Step Diagnostic Procedure

  1. Monitor bank 2 pumping current for high readings

  2. Check bank 2 wiring for short to power

  3. Inspect bank 2 sensor tip for contamination

  4. Test ECM bank 2 O2 output

Frequently Asked Questions

Can a lean bank 2 cause engine damage?

Prolonged lean operation on bank 2 can cause elevated exhaust temperatures, potentially damaging catalytic converters and in extreme cases, causing cylinder damage.

What does coolant contamination on an O2 sensor look like?

A white or crystalline coating on the sensor tip indicates coolant has reached the exhaust system, usually from a head gasket leak or cracked head.

Will P2631 cause a failed emissions test?

Yes. The incorrect bank 2 readings will cause improper fuel trim, likely resulting in high NOx emissions from the lean condition.

Sources

This page is built from documented references. Verify against your own service info before repair work.

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