P0055 low

Heated Oxygen Sensor Heater Resistance (Bank 1, Sensor 3)

The P0055 code means the vehicle's onboard diagnostic system has detected: Heated Oxygen Sensor Heater Resistance (Bank 1, Sensor 3). This is a low severity code.

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Keep driving?
Yes, but fix soon
DIY difficulty
easy
Estimated cost
$100 - $300 (parts and labor)
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Common Symptoms

  • Check Engine Light on
  • Slight decrease in fuel economy
  • Extended time for O2 sensor to reach operating temperature
  • Potential emissions test failure

Probable Causes (Ranked by Likelihood)

  • Degraded heater element in Bank 1 Sensor 3 Very High
  • High-resistance connection at sensor connector High
  • Wiring damage between ECM and sensor Moderate
  • Aftermarket O2 sensor with incorrect resistance Low

Step-by-Step Diagnostic Procedure

  1. Confirm P0055 and locate Bank 1 Sensor 3

  2. Measure heater element resistance at sensor connector

  3. Compare to manufacturer specification for heater resistance

  4. Check wiring and connector integrity

Frequently Asked Questions

What does P0055 mean?

P0055 indicates the heater resistance in the Bank 1 Sensor 3 oxygen sensor is outside the normal specification, typically from a worn heater element.

Do all cars have a Sensor 3?

No, only vehicles with multiple catalytic converters (usually V6 or V8 engines) have a Sensor 3 position. Four-cylinder engines typically only have Sensor 1 and Sensor 2.

Can I drive with P0055?

Yes, P0055 is low severity and does not significantly affect driveability. However, it may cause an emissions test failure.

Sources

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

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