P0175 on a Toyota: Causes, Fixes & Repair Cost

🟠 Moderate severity · drivable

Drivable for a short time, but a rich mixture wastes fuel and can damage the catalytic converter, so fix it soon.

What P0175 means on a Toyota

On a Toyota, P0175 means bank 2 is running rich — too much fuel or not enough air. Toyota V6 and V8 engines use air/fuel ratio sensors that can fail and misreport the mixture. The engine may run rough or smell of fuel until it's fixed.

Is P0175 common on Toyotas?

P0175 only appears on Toyotas with a second cylinder bank, like the Camry V6, Avalon, Highlander, and 4Runner. On higher-mileage Toyotas the air/fuel ratio sensor and mass air flow sensor are the usual suspects. An exhaust leak ahead of the sensor can also fool the reading.

Commonly reported on: Camry, Avalon, Highlander, 4Runner.

Symptoms

Check engine light is on
Poor fuel economy
Strong fuel smell
Rough idle

Common causes

most common: Faulty air/fuel ratio sensor on bank 2
common: Dirty or failing mass air flow sensor
common: Exhaust leak ahead of the bank 2 sensor
less common: Leaking fuel injector on bank 2

How to fix it

Fix	DIY?	Typical cost
Replace the bank 2 air/fuel ratio sensor	Yes	$80–250
Clean or replace the mass air flow sensor	Yes	$10–250
Repair the exhaust leak ahead of the sensor	Mechanic	$100–300