AutoCodes – Buick – P2273 Buick

P2273 Buick Code - HO2S Signal Stuck Rich Bank 2 Sensor 2

Quick Answer

The Heated Oxygen Sensors (HO2S) are used for fuel control and catalyst monitoring. Common causes include Faulty Heated Oxygen Bank 2 Sensor 2, Heated Oxygen Bank 2 Sensor 2 harness is open or shorted, Heated Oxygen Bank 2 Sensor 2 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: P2273 Buick indicates HO2S Signal Stuck Rich Bank 2 Sensor 2.
Common causes: Common causes include Faulty Heated Oxygen Bank 2 Sensor 2, Heated Oxygen Bank 2 Sensor 2 harness is open or shorted, Heated Oxygen Bank 2 Sensor 2 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 704

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 May 28, 2022

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P2273 Buick Description

The Heated Oxygen Sensors (HO2S) are used for fuel control and catalyst monitoring. Each HO2S compares the oxygen content of the surrounding air with the oxygen content of the exhaust stream. When the engine is started, the Engine Control Module (ECM) operates in an Open Loop mode, ignoring the HO2S signal voltage while calculating the air-to-fuel ratio. While the engine runs, the HO2S heats up and begins to generate a voltage within a range of 0 - 1, 000 mV. Once sufficient HO2S voltage fluctuation is observed by the ECM, Closed Loop is entered. The ECM uses the HO2S voltage to determine the air-to-fuel ratio. An HO2S voltage that increases toward 1, 000 mV indicates a rich fuel mixture. An HO2S voltage that decreases toward 0 mV indicates a lean fuel mixture.
The heating elements inside each HO2S heat the sensor to bring the sensor up to operating conditions faster. This allows the system to enter Closed Loop earlier and the ECM to calculate the air-to-fuel ratio sooner.
The Diagnostic Trouble Code (DTC) will be set when the ECM does not detect an HO2S voltage less than 100 mV before accumulated mass airflow exceeds a calibrated value.

OBDII Code P2273 Buick - HO2S Signal Stuck Rich Bank 2 Sensor 2 - AutoCodes.com — P2273 Buick Code - HO2S Signal Stuck Rich Bank 2 Sensor 2

What does this mean?

What are the Possible Causes of the DTC P2273 Buick?

Faulty Heated Oxygen Bank 2 Sensor 2
Heated Oxygen Bank 2 Sensor 2 harness is open or shorted
Heated Oxygen Bank 2 Sensor 2 circuit poor electrical connection
Low or high fuel system pressure
Fuel contamination
Faulty fuel injectors
Exhaust gas leaks
Engine vacuum leaks

How to Fix the DTC P2273 Buick?

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 Rear Heated Oxygen Sensors (HO2S) usually takes care of the problem.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P2273 Buick 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 P2273 Buick code?

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Need Help with the Code?

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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 P2273 Buick Code

1. What are the common symptoms of OBDII code P2273 in a Buick?

The common symptoms of code P2273 include poor fuel economy, black smoke from the exhaust, rough idling, and a noticeable decrease in engine performance.

2. What does the OBDII code P2273 "HO2S Signal Stuck Rich Bank 2 Sensor 2" mean for a Buick?

This code indicates that the downstream oxygen sensor in bank 2 of the Buick's engine is detecting a consistently rich air-fuel mixture.

3. What are the possible causes of OBDII code P2273 in a Buick?

Possible causes of code P2273 in a Buick include a faulty oxygen sensor, a vacuum leak, a malfunctioning fuel injector, or a problem with the engine's air intake system.

4. How can I diagnose the OBDII code P2273 in my Buick?

Diagnosing code P2273 involves using an OBDII scanner to retrieve the code, inspecting the oxygen sensor in bank 2 sensor 2, checking for vacuum leaks, and testing the fuel injectors and air intake system for issues.

5. Can I continue driving my Buick with OBDII code P2273 present?

It is not recommended to continue driving your Buick with code P2273 present, as it can lead to further damage to the engine and negatively impact fuel efficiency.

6. How can I repair OBDII code P2273 in my Buick?

Repairing code P2273 may involve replacing the downstream oxygen sensor in bank 2 sensor 2, fixing any vacuum leaks, addressing fuel injector issues, or repairing problems in the air intake system.

7. Is it possible to clear OBDII code P2273 in a Buick without making any repairs?

While clearing the code without addressing the underlying issue may temporarily turn off the check engine light, the problem causing code P2273 will likely persist and trigger the code again in the future.

8. Can a DIY enthusiast fix OBDII code P2273 in a Buick?

Depending on their skill level and access to tools, a DIY enthusiast may be able to address OBDII code P2273 by following repair guides and diagnostic procedures, but professional help is recommended for accurate diagnosis and repair.

9. How much can I expect to pay for repairing OBDII code P2273 in a Buick?

The cost of repairing code P2273 in a Buick can vary depending on the specific issue causing the code, the labor rates in your area, and the parts needed for the repair. It is recommended to obtain quotes from local mechanics or repair shops.

10. Will fixing OBDII code P2273 improve my Buick's performance and fuel efficiency?

Yes, addressing and repairing code P2273 in your Buick should improve engine performance, fuel efficiency, and overall drivability by ensuring the correct air-fuel mixture is maintained.