🔍

P0177: Fuel Composition Sensor Circuit Range/Performance

Severity
Low
NHTSA Reports
1
Vehicles Affected
1
System
Powertrain

What Does P0177 Mean?

P0177 is a diagnostic trouble code indicating: Fuel Composition Sensor Circuit Range/Performance. This code relates to the fuel and air metering system. It has been reported in NHTSA complaints across 1 different vehicle models.

Symptoms of P0177

Real Owner Reports

From NHTSA complaint database — actual owner descriptions.

"The contact owns a 2019 Subaru Outback. The contact stated while driving approximately 60 MPH, the vehicle inadvertently decelerated while the accelerator pedal remained depressed. The engine misfired and the vehicle stalled. The check engine warning light illuminated, then several other unknown war"

— Subaru Outback owner, 05/20/2023

Source: NHTSA Complaints Database

Most Reported Vehicles for P0177

Based on NHTSA owner complaint data.

# Vehicle Reports
1 SUBARU OUTBACK

Frequently Asked Questions

Can I drive with this code?
You can usually drive short distances, but fuel economy will suffer and emissions will be higher. Get it diagnosed within a week.
Will this code cause my car to fail emissions?
Yes — any active check engine light will cause an automatic emissions test failure in most states.
How much does it typically cost to fix?
Depends on the root cause. Simple fixes like a gas cap ($5-15) to sensor replacement ($150-300) to more complex repairs ($500+).

What To Do Next

Possible Fixes

  • 🔧 Have the code scanned with a professional-grade scanner to read freeze frame data
  • 🔧 Clean or replace the mass air flow (MAF) sensor; check for vacuum leaks
  • 🔧 If DIY repair isn't feasible, get a diagnostic from a trusted mechanic ($50-150)
  1. 1
    Find your vehicle above

    Click your make and model for real owner reports and common causes specific to your vehicle.

  2. 2
    Check for recalls

    Go to nhtsa.gov/recalls and enter your VIN. Free repairs if covered.

  3. 3
    Get a professional diagnosis

    A code alone doesn't identify the exact failed part. A diagnostic ($50–$150) pinpoints the root cause.

Related Codes

P0100 Mass or Volume Air Flow Sensor A Circuit P0101 Mass or Volume Air Flow Sensor A Circuit Range/Performance P0102 Mass or Volume Air Flow Sensor A Circuit Low P0103 Mass Air Flow Circuit High Input P0104 Mass or Volume Air Flow Sensor A Circuit Intermittent P0105 Manifold Absolute Pressure/Barometric Pressure Sensor Circuit P0106 Manifold Absolute Pressure/Barometric Pressure Sensor Circuit Range/Performance P0107 Manifold Absolute Pressure/Barometric Pressure Sensor Circuit Low P0108 Manifold Absolute Pressure/Barometric Pressure Sensor Circuit High P0109 Manifold Absolute Pressure/Barometric Pressure Sensor Circuit Intermittent