AutoCodes – Generic – P0163

P0163 Code - O2 Sensor Circuit Low Voltage Bank 2 Sensor 3

Quick Answer

The rear heated oxygen sensor (or sensor 3 for some vehicles), after three way catalyst (manifold), monitors the oxygen level in the exhaust gas on each bank. Common causes include Faulty Heated Oxygen Sensor Bank 2 Sensor 3, Heated Oxygen Sensor Bank 2 Sensor 3 harness is open or shorted, Heated Oxygen Sensor Bank 2 Sensor 3 circuit poor electrical connection. Severity is Moderate - service should be scheduled soon. The vehicle may still be drivable for short trips if it runs normally, but avoid hard driving and repair it soon.

What it means: P0163 indicates O2 Sensor Circuit Low Voltage Bank 2 Sensor 3.
Common causes: Common causes include Faulty Heated Oxygen Sensor Bank 2 Sensor 3, Heated Oxygen Sensor Bank 2 Sensor 3 harness is open or shorted, Heated Oxygen Sensor Bank 2 Sensor 3 circuit poor electrical connection.
Severity: Moderate - service should be scheduled soon.
Can I drive?: The vehicle may still be drivable for short trips if it runs normally, but avoid hard driving and repair it soon.

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Code Popularity 14,756

How popular is this code, among other codes? Low

Repair Importance Level

Moderate (Service soon) (2 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jun 14, 2020

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
Comments
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Code P0163 Description

The rear heated oxygen sensor (or sensor 3 for some vehicles), after three way catalyst (manifold), monitors the oxygen level in the exhaust gas on each bank. Even if switching characteristics of the heated oxygen sensor 1 are shifted, the air-fuel ratio is controlled to stoichiometric, by the signal from the heated oxygen sensor 3. This sensor is made of ceramic zirconia. The zirconia generates voltage from approximately 1V in richer conditions to 0V in leaner conditions. Under normal conditions the heated oxygen sensor 3 is not used for engine control operation.

OBDII Code P0163 - O2 Sensor Circuit Low Voltage Bank 2 Sensor 3 - AutoCodes.com — P0163 Code - O2 Sensor Circuit Low Voltage Bank 2 Sensor 3

What does this mean?

What are the Possible Causes of the DTC P0163?

Faulty Heated Oxygen Sensor Bank 2 Sensor 3
Heated Oxygen Sensor Bank 2 Sensor 3 harness is open or shorted
Heated Oxygen Sensor Bank 2 Sensor 3 circuit poor electrical connection

How to Fix the DTC P0163?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What does this mean?

Code Tech Notes

Replacing the O2 Sensor 3 usually takes care of the problem

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0163 code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the P0163 code?

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Need Help with the Code?

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Information for Specific Makes

P0163 Mercedes-Benz — O2 Sensor Circuit Low Voltage Bank 2 Sensor 3

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.