P0175
System Too Rich (Bank 2)
Same condition as P0172 but on bank 2. When paired with P0172, suspect shared causes (fuel pressure, blocked air filter); when alone, suspect a bank-specific injector or oxygen sensor.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: medium
What we see in the workshop
ON FORD ECOBOOST
As with P0172 — on a V6 EcoBoost, both banks rich points at a shared fuel pressure or sensor fault.
Symptoms
- Check engine light on
- Increased fuel consumption
- Black smoke from exhaust on acceleration
- Smell of unburned fuel, fouled spark plugs
Common causes
Ordered by how often each turns out to be the cause.
- Fuel pressure regulator stuck closedCommon
- Leaking fuel injector on bank 2Possible
Parts involved
- Fuel Pressure Regulator
- Fuel Injector
- Oxygen Sensor Upstream
P0175 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.