P0175: System Too Rich (Bank 2)

written by Edmunds.com^{This story was created with generative AI and was reviewed and fact-checked by our staff of editors and experts.}
edited by Chase Bierenkoven^{Contributor
Chase Bierenkoven has been writing about cars in his head since he was a child. Now, he does it for real, covering automotive news and producing reviews for outlets like Edmunds, Forbes Wheels and CarBuzz. Chase's career as an automotive journalist began in 2020, and he has already written scores of road tests. Some favorites of Chase's include the Dodge Challenger 392, Mazda Miata, Kia EV6 and Bentley Bentayga. Outside his work with cars, Chase is often found justifying his latest broken German sports car to anyone that will listen or enjoying the outdoor spaces of his native Colorado.}
12/20/2024
Share:

What does the P0175 error code mean?

The P0175 diagnostic trouble code signifies "System Too Rich (Bank 2)." This code is triggered when the engine control module detects an overly rich air-fuel mixture in bank two. A "rich" condition means there is too much fuel and not enough air in the mixture — sometimes called the air-fuel ratio — which can affect engine performance and emissions.

Why it's important to address the P0175 error code

An overrich air-fuel mixture can lead to poor fuel efficiency, increased emissions, and potential damage to the engine or catalytic converter over time. Excess fuel in exhaust gases can cause the catalytic converter to overheat and fail, leading to costly repairs. Addressing the issue promptly is critical to maintaining engine health and emissions compliance.

Can I safely drive my car with this error code?

Driving with the P0175 code is not recommended. While your car might start and drive, you may encounter performance issues such as rough idling or reduced power. Continuing to drive with a rich air-fuel ratio can damage the catalytic converter or other engine components, increasing repair costs.

Common symptoms of the P0175 error code

Illuminated check engine light
Poor fuel economy
Strong fuel smell from the exhaust
Rough idling or stalling
Hesitation or lack of power during acceleration
Dark exhaust smoke (in severe cases)

How to diagnose the P0175 error code

Diagnosing the P0175 code involves the following steps:

Scan for codes: Use an OBD-II scanner to confirm the P0175 code and check for related codes.
Inspect air intake: Look for obstructions, such as a clogged air filter, that could reduce airflow.
Check fuel system: Test the fuel injectors for leaks or malfunctions and verify fuel pressure is within specification.
Inspect oxygen sensors: Evaluate the upstream and downstream oxygen sensors in bank two for proper operation.
Examine mass air flow sensor: Ensure the mass air flow sensor is clean and functioning correctly because it affects air-fuel calculations.
Check for exhaust leaks: Inspect the exhaust system for leaks near the oxygen sensors.

How to repair the P0175 error code

Repairing the P0175 code typically involves:

Replacing a clogged air filter to restore proper airflow.
Repairing or replacing leaking or malfunctioning fuel injectors.
Cleaning or replacing a faulty mass air flow sensor.
Replacing a damaged or malfunctioning oxygen sensor in bank two.
Repairing any exhaust leaks near the oxygen sensors.
Adjusting or replacing the fuel pressure regulator if the fuel pressure is too high.
Clearing the code and performing a test drive to ensure the repair was successful.