AutoCodes – Generic – P11B3

P11B3 Code - HO2S Performance During Deceleration Fuel Cut-Off Bank 1 Sensor 2

Quick Answer

The oxygen content of the exhaust is measured via the nitrogen oxide (NOx) sensors. Common causes include Faulty Nitrogen Oxide (NOx) Sensor 2, Nitrogen Oxide Sensor 2 harness is open or shorted, Nitrogen Oxide Sensor 2 circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: P11B3 indicates HO2S Performance During Deceleration Fuel Cut-Off Bank 1 Sensor 2.
Common causes: Common causes include Faulty Nitrogen Oxide (NOx) Sensor 2, Nitrogen Oxide Sensor 2 harness is open or shorted, Nitrogen Oxide Sensor 2 circuit poor electrical connection.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 2,276

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

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Table of contents Created and updated by William Orellana on Sep 30, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P11B3 Description

The oxygen content of the exhaust is measured via the nitrogen oxide (NOx) sensors. The nitrogen oxides (NOx) sensors are part of the selective catalytic reduction system, a device used to reduce NOx emission on diesel engines. There are two NOx sensors, one placed upstream of selective catalytic reduction, to measure inlet NOx concentration, and one placed downstream. They are connected with the control module via CAN and all the information is exchanged through it. Since it is a smart sensor, all the electrical monitoring is performed inside the sensor and only the results are sent to the ECM. Each NOx sensor contains a sensing cell, a pumping cell, and a heater. A sample of exhaust gas passes through a diffusion gap between the sensing cell and the pumping cell. The NOx sensor maintains a constant reference voltage across the sensing cell. An electronic circuit within sensor controls the pump current through the pumping cell in order to maintain a constant voltage in the sensing cell. The amount of current required to maintain the reference voltage in the sensing cell is proportional to the concentration of NOx in the exhaust. The ECM varies the amount of diesel exhaust fluid (reductant) added by varying the reductant injector duty cycle in response to changes in engine exhaust NOx levels. The smart NOx sensors consist of two components, the NOx module and the NOx sensor element that are serviced as a unit. A circuit or performance condition with a NOx sensor is detected by the NOx sensor module. The smart NOx sensor module communicates the condition to the ECM over the serial data line. The ECM sets a DTC when a serial data message is received from the NOx sensor module. The Diagnostic Trouble Code (DTC) will be set when the NOx sensor module detects a fault in the NOx sensor circuitry or a performance fault in the NOx sensor.

OBDII Code P11B3 - HO2S Performance During Deceleration Fuel Cut-Off Bank 1 Sensor 2 - AutoCodes.com — P11B3 Code - HO2S Performance During Deceleration Fuel Cut-Off Bank 1 Sensor 2

What does this mean?

What are the Possible Causes of the DTC P11B3?

Faulty Nitrogen Oxide (NOx) Sensor 2
Nitrogen Oxide Sensor 2 harness is open or shorted
Nitrogen Oxide Sensor 2 circuit poor electrical connection

How to Fix the DTC P11B3?

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 is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P11B3 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 P11B3 code?

Need more information on how to fix the P11B3 code? Get Access to Factory Service Manuals

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Information for Specific Makes

P11B3 Buick — HO2S Performance During Deceleration Fuel Cut-Off Bank 1 Sensor 2
P11B3 Cadillac — HO2S Performance During Deceleration Fuel Cut-Off Bank 1 Sensor 2
P11B3 Chevrolet — HO2S Performance During Deceleration Fuel Cut-Off Bank 1 Sensor 2
P11B3 GMC — HO2S Performance During Deceleration Fuel Cut-Off Bank 1 Sensor 2

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.

Frequently Asked Questions about P11B3 Code

1. What are common symptoms of OBDII code P11B3?

- Common symptoms include poor fuel economy, rough idling, hesitation or stalling when decelerating, and illuminated check engine light.

2. What does the OBDII code P11B3 indicate?

- P11B3 indicates a performance issue with the oxygen sensor (HO2S) during deceleration fuel cut-off for Bank 1 Sensor 2 in the vehicle's exhaust system.

3. What are the possible causes of OBDII code P11B3?

- Possible causes include a faulty oxygen sensor (HO2S), wiring issues, vacuum leaks, exhaust system leaks, fuel system problems, or issues with the engine control module (ECM).

4. How can I diagnose the OBDII code P11B3?

- Diagnosing P11B3 involves using an OBDII scanner to read the code, checking the oxygen sensor for proper operation, inspecting wiring connections, and performing a thorough visual inspection of the exhaust system.

5. Can I continue driving with OBDII code P11B3?

- It is not recommended to ignore OBDII code P11B3, as it can lead to poor engine performance and potentially cause damage to the catalytic converter. It is best to address the issue promptly.

6. How can I repair OBDII code P11B3?

- Repairing P11B3 may involve replacing the oxygen sensor (HO2S), repairing any wiring or exhaust leaks, addressing fuel system issues, or reprogramming the engine control module (ECM) if necessary.

7. Is it possible to reset OBDII code P11B3 without fixing the underlying issue?

- Resetting the code without addressing the underlying issue will only temporarily clear the check engine light. The problem causing P11B3 will likely persist, leading to the code reappearing.

8. How long does it take to repair OBDII code P11B3?

- The repair time for P11B3 can vary depending on the specific cause of the issue. Simple fixes like replacing the oxygen sensor may take less than an hour, while more complex issues could require more time.

9. Are there any DIY repair options for OBDII code P11B3?

- DIY repair options for P11B3 include replacing the oxygen sensor or checking for obvious wiring or exhaust leaks. However, more advanced diagnostics and repairs may require professional assistance.

10. Can a mechanic help me diagnose and repair OBDII code P11B3?

- Yes, a qualified mechanic can use specialized tools and knowledge to accurately diagnose and repair OBDII code P11B3, ensuring the issue is properly resolved.