2017 Mitsubishi P0172: What It Means & Is It Safe to Drive?
P0172 on the 2017 Mitsubishi: System Too Rich (Bank 1). Here's what it means, what usually causes it, what repairs typically cost, and whether it's safe to keep driving.
PowertrainMedium urgency
What this code means
Too much fuel relative to air. O2 sensor detects low oxygen in exhaust; PCM is reducing fuel trim.
Common causes on the 2017 Mitsubishi
- Faulty MAF or O2 sensor
- Leaking fuel injector(s)
- High fuel pressure
- Faulty purge valve stuck open
Symptoms
- Check Engine Light
- Rich smell, black smoke
- Poor fuel economy
- Rough idle possible
Typical fixes
- Replace MAF or O2 sensor
- Test fuel pressure and injectors
- Replace purge valve if stuck open
Repair cost range
For a 2017 Mitsubishi, repairs for P0172 typically fall between $100 and $600, depending on the root cause and labor rates in your area.
Known issues on Mitsubishi
Mitsubishi 4G69 P0172 rich Bank 1 is typically a stuck-open EVAP purge valve or a leaking fuel injector. On older 4G63 turbo models, a failing boost sensor or fuel pressure regulator can cause over-fueling. Check the purge valve first, then fuel pressure regulator.
Most commonly affected models
Outlander 2.4L 4G69 2004–2012Lancer 2.0L 4G63 2002–2007