P0175 on a GMC: Causes, Fixes & Repair Cost

🟠 Moderate severity · drivable

Drivable short-term, but a rich mixture wastes fuel and can foul plugs or overheat the catalytic converter if ignored.

What P0175 means on a GMC

On a GMC, P0175 means the engine is running rich on bank 2 — too much fuel or too little air on the side opposite cylinder 1. GMC trucks and SUVs with V6 or V8 engines have two banks, and this code points to the second one. The computer has already trimmed fuel as far as it can.

Is P0175 common on GMCs?

P0175 appears on GMC V8 models like the Sierra and Yukon, and on V6 models like the Acadia. Leaking fuel injectors are a well-known cause on GM V8s, and a dirty mass air flow sensor is also common. A slow oxygen sensor can keep the mixture rich on higher-mileage trucks.

Commonly reported on: Sierra, Yukon, Acadia, Terrain.

Symptoms

Check engine light is on
Poor fuel economy
Fuel smell from the exhaust
Rough idle or hesitation

Common causes

most common: Leaking fuel injector on bank 2
common: Dirty or failing mass air flow (MAF) sensor
common: Slow or failing oxygen sensor on bank 2
less common: Fuel pressure too high
less common: Clogged air filter

How to fix it

Fix	DIY?	Typical cost
Clean the MAF sensor with MAF cleaner spray	Yes	$10–20
Replace the leaking injector on bank 2	Mechanic	$250–650
Replace the bank 2 upstream oxygen sensor	Yes	$80–250
Check fuel pressure and the regulator	Mechanic	$100–300

Frequently asked questions

Which GMC models see P0175?

Trucks and SUVs with V6 or V8 engines, like the Sierra, Yukon, and Acadia. Four-cylinder models don't have a bank 2.

Why are leaking injectors common on GMC V8s?

The fuel injectors on GM V8 engines can develop internal leaks at higher mileage, letting extra fuel into a cylinder. That is a classic cause of a rich bank code.

Is it safe to drive my GMC with P0175?

Short trips are fine, but a rich mixture can foul plugs and overheat the catalytic converter over time. Get it diagnosed soon.