OBD Guide

P0161

O2 Sensor Heater Circuit Bank 2 Sensor 2

P0161 is an OBD-II diagnostic trouble code meaning: O2 Sensor Heater Circuit Bank 2 Sensor 2. Common causes: malfunction of the oxygen sensor (lambda probe), open or short circuit in the heater circuit. Estimated repair cost: $56–167.

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$56–167 (est.)

Symptoms

  • Increased fuel consumption
  • Unstable engine operation at idle
  • Check Engine Light Is On
  • Increased level of harmful emissions

Causes

  • Malfunction of the oxygen sensor (lambda probe)
  • Open or short circuit in the heater circuit
  • Wiring harness damage
  • Faulty relay or fuse
  • Problems with the ECU

How to Fix

  1. Check the resistance of the sensor heater (should be within 5-20 Ohms)
  2. Check the integrity of wiring and connectors
  3. Check the voltage in the heater circuit (usually 12 V)
  4. Replace the oxygen sensor if necessary
  5. Check and replace fuse or relay if necessary

Related codes

Error P0161 by Vehicle Brand

FAQ

What does the P0161 code mean?

P0161 is an OBD-II diagnostic trouble code that indicates: O2 Sensor Heater Circuit Bank 2 Sensor 2

What causes a P0161 error code?

The most common causes of P0161 include: Malfunction of the oxygen sensor (lambda probe); Open or short circuit in the heater circuit; Wiring harness damage; Faulty relay or fuse.

How do I fix a P0161 diagnostic trouble code?

To fix P0161: Check the resistance of the sensor heater (should be within 5-20 Ohms). Check the integrity of wiring and connectors. Check the voltage in the heater circuit (usually 12 V). For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P0161?

Limited driving only, diagnose soon

How much does it cost to fix P0161?

The estimated repair cost for P0161 is $56–167. Actual cost depends on your vehicle, location, and labor rates.

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