Engine-CodesGeneric – P0173

P0173 Code - Fuel Trim Malfunction Bank 2

Quick Answer

The P0173 code indicates a fuel trim malfunction in Bank 2 of the engine. Common causes include Faulty oxygen sensor, Vacuum leaks in the intake system, Fuel injector issues. 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
P0173 indicates Fuel Trim Malfunction Bank 2.
Common causes
Common causes include Faulty oxygen sensor, Vacuum leaks in the intake system, Fuel injector issues.
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.
Table of contents Created and updated by William Orellana on Aug 18, 2024
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Code P0173 Description

The P0173 code indicates a fuel trim malfunction in Bank 2 of the engine. This means that the engine control module (ECM) is detecting that the air-fuel mixture is either too lean or too rich on the bank 2 side of the engine. This can lead to inefficient combustion, reduced fuel economy, and increased emissions. If not addressed, this issue can potentially damage the catalytic converter and other components of the engine over time.

OBDII Code P0173 - Fuel Trim Malfunction Bank 2
P0173 Code - Fuel Trim Malfunction Bank 2

Common Causes of P0173

  1. Faulty oxygen sensor
  2. Vacuum leaks in the intake system
  3. Fuel injector issues
  4. Faulty Mass Air Flow (MAF) sensor
  5. Issues with the fuel pressure regulator

Symptoms of P0173

  1. Check Engine Light is illuminated
  2. Decreased fuel efficiency
  3. Rough idling or engine misfires
  4. Hesitation or lack of power during acceleration
  5. Strong fuel odor from the exhaust

How to Fix P0173

  1. Use a scan tool to identify the specific cause of the fuel trim malfunction.
  2. Inspect and replace any faulty oxygen sensors or sensors related to the air-fuel mixture.
  3. Check for and repair any vacuum leaks in the intake system.
  4. Test and potentially replace fuel injectors if they are not functioning correctly.
  5. Verify and possibly replace the Mass Air Flow sensor if it is causing the issue.

Cost to Fix P0173

The cost of repairing a P0173 code can vary depending on the specific cause of the issue. On average, the repair costs can range from $200 to $500, including parts and labor. Keep in mind that rates for diagnosis and labor can vary depending on the location, vehicle make and model, and the type of engine. It's best to consult with a trusted auto repair shop for an accurate estimate.

Tech Notes for P0173

A dirty air filter or a faulty air flow sensor are a common cause for the P0173 code of the problem.





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When is the Code Detected?

- Fuel injection system does not operate properly.
- The amount of mixture ratio compensation is not correct

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Code P0173 Information for Specific Makes

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 P0173 Code

1. What are common symptoms of OBDII code P0173 (Fuel Trim Malfunction Bank 2)?

- Common symptoms include rough idling, decreased fuel efficiency, engine misfires, and a noticeable decrease in engine performance.

2. What are the possible causes of OBDII code P0173 (Fuel Trim Malfunction Bank 2)?

- Potential causes include a vacuum leak, faulty oxygen sensor, clogged fuel injectors, fuel pressure regulator issues, or a malfunctioning mass airflow sensor.

3. How can I diagnose the OBDII code P0173 (Fuel Trim Malfunction Bank 2)?

- Diagnosis typically involves using an OBDII scanner to retrieve the code, inspecting the affected bank's oxygen sensor, checking for vacuum leaks, and testing the fuel injectors and other related components.

4. Can a dirty or clogged air filter trigger OBDII code P0173 (Fuel Trim Malfunction Bank 2)?

- Yes, a dirty or clogged air filter can disrupt the air-fuel mixture ratio, potentially leading to a lean condition in Bank 2 and triggering the P0173 code.

5. What should I do if I get OBDII code P0173 (Fuel Trim Malfunction Bank 2)?

- It is recommended to address the underlying issue promptly to prevent further damage to the engine. Consult a mechanic to accurately diagnose and repair the problem.

6. How can I prevent OBDII code P0173 (Fuel Trim Malfunction Bank 2) from occurring?

- Regular maintenance, such as changing the air filter and ensuring all engine components are in good working condition, can help prevent issues that may trigger the P0173 code.

7. Can driving with OBDII code P0173 (Fuel Trim Malfunction Bank 2) cause long-term damage to the vehicle?

- Continuing to drive with this code may lead to reduced engine performance, decreased fuel efficiency, and potential damage to the catalytic converter over time.

8. Is it safe to clear OBDII code P0173 (Fuel Trim Malfunction Bank 2) using an OBDII scanner?

- Clearing the code without addressing the underlying issue may temporarily turn off the check engine light, but the problem will persist and likely trigger the code again in the future.

9. How much does it typically cost to repair OBDII code P0173 (Fuel Trim Malfunction Bank 2)?

- The cost of repair varies depending on the cause of the issue, but it can range from a simple fix like replacing a faulty sensor to a more complex repair involving multiple components.

10. Can a DIY enthusiast fix OBDII code P0173 (Fuel Trim Malfunction Bank 2) at home?

- While some causes of the P0173 code may be addressed by DIY enthusiasts, it's recommended to consult a professional mechanic for an accurate diagnosis and proper repair to ensure the issue is fully resolved.

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