Generic OBD2 code · Fuel and air metering

P0175: System Too Rich (Bank 2)

The engine computer has removed as much fuel as it can on bank 2 and the upstream oxygen sensor on that bank still sees a rich mixture.

CodeP0175

SystemFuel and air metering

Typical urgencyModerate to high

Can I keep driving?Usually drivable short term, but a rich mixture wastes fuel and can harm the catalytic converter, so diagnose it soon.

What does P0175 mean?

P0175 is the bank 2 version of P0172. Bank 2 is the side of a V6, V8 or V10 engine that does not contain cylinder 1, so this code does not appear on inline four cylinder engines.

The ECM uses negative fuel trim to take fuel away when the mixture is rich. When that correction reaches its limit, it stores P0175. It is common to see P0172 and P0175 together, which points to a cause that affects both banks.

Common symptoms

Check engine light on
Often no noticeable drivability change
Possible misfire or rough idle
Lack of power on acceleration in some cases

Common causes

The causes below are the ones commonly seen with P0175. The actual cause can vary by vehicle, engine and mileage, so treat this list as a starting point, not a diagnosis.

A dirty or faulty mass air flow (MAF) sensor
High fuel pressure or a faulty fuel pressure regulator
Leaking or dirty fuel injectors on bank 2
A faulty oxygen sensor on bank 2 or another input sensor

What to check with a scanner

Compare bank 1 and bank 2 fuel trims in Live data. Only bank 2 rich points to something on that side, such as an injector or the bank 2 oxygen sensor.
Check the MAF reading and the coolant temperature reading for values that do not make sense.
Read freeze frame data and any other codes before clearing.

How to read and clear P0175 with OBD Master Pro

Plug in your adapter. Connect a generic ELM327 (or ELM329) OBD2 adapter to the diagnostic port, usually under the dashboard on the driver's side. Bluetooth Classic, Bluetooth LE, Wi-Fi and USB OTG adapters are supported.
Switch the ignition on. Turn the key to ON or start the engine, depending on your car.
Connect in OBD Master Pro. Open the app, go to Connection and pick your adapter. Classic Bluetooth adapters connect from the Bluetooth tab, Bluetooth LE adapters from the BLE tab with no pairing needed. Use the generic OBD2 / EOBD profile or your car's brand profile.
Read the codes. Open the fault codes screen to see stored, pending and permanent codes. Confirm P0175 is listed and note any other codes, since they often explain the cause.
Check the details. Look at freeze frame data, Live data and, where your car supports it, Mode 06 test results (see the checks above).
Fix, then clear. After the repair, clear the codes to turn off the check engine light. Clearing also resets the emissions readiness monitors, so drive normally and check the readiness screen before any inspection. Permanent codes cannot be erased with a scan tool; they clear on their own once the car's self test passes.

Tip: you can also look up P0175 and other codes in the app's DTC search without connecting to a car. If your adapter will not connect, use Connection > Share connection log and email it to support. Many cheap ELM327 clones only handle basic engine OBD2, which is all you need for P0175.

When to see a mechanic

Get professional help if any of these apply:

You smell raw fuel
The check engine light flashes or the engine misfires
Fuel pressure needs to be tested with a gauge

If you are unsure, a qualified technician can confirm the cause with tests such as smoke testing, pressure testing or scope readings. Clearing a code does not repair the fault.

P0175 FAQ

Does P0175 mean I need new injectors?

Not necessarily. MAF sensor readings and fuel pressure are common causes too. Check those before replacing injectors.

Why do I have P0172 and P0175 together?

When both banks are rich, the cause is usually shared, such as a MAF sensor reporting the wrong airflow or fuel pressure that is too high.

Can I drive with P0175?

Usually for a short time if the car runs normally. Continued rich running can damage the catalytic converter.

Check P0175 on your own car

OBD Master Pro turns your Android phone and a generic ELM327 adapter into a code reader: read and clear codes, view freeze frame and live data, and check emissions readiness.

Sources

Published October 24, 2026. Updated October 24, 2026. This guide is general information for generic SAE codes. Always follow the service information for your specific vehicle.