OBD-II code · Powertrain (generic)
P0177 Fuel Composition Sensor Circuit Range / Performance
The flex-fuel composition sensor signal is within electrical limits but does not match expected values for the current fuel mix or rate-of-change is implausible.
Is it safe to drive with P0177?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelySensor drifted out of calibration
- PossibleFuel contaminated (water, dirt)
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.5–2 h
- Emissions test
- Likely to fail
- Parts involved
- Flex Fuel Composition Sensor
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.