P0479
Exhaust Pressure Control Valve Intermittent
Lowexhaust
Overview
The P0479 code means the PCM has detected a exhaust pressure control valve intermittent fault. This code relates to the exhaust system components that manage and monitor exhaust gas flow and pressure. An issue in the exhaust system can affect engine efficiency, emissions output, and overall vehicle performance.
Symptoms
- Poor fuel economy
- Excessive exhaust smoke
- Failed emissions test
- Exhaust smell inside the cabin
Common Causes
- Failed exhaust pressure control valve
- Carbon buildup in exhaust system
- Wiring issues in exhaust sensor circuit
- Cracked or leaking exhaust pipes
Diagnosis Steps
- 1Connect an OBD-II scanner and read all stored trouble codes and freeze frame data
- 2Visually inspect the exhaust system for leaks, cracks, or damage
- 3Test the exhaust pressure sensor with a multimeter
- 4Check the exhaust pressure control valve for proper operation
- 5Inspect wiring and connectors for the exhaust pressure circuit
Estimated Repair Cost
$150 — $1,200
Cost varies by vehicle, location, and repair shop. Includes parts and labor.
Commonly Affected Vehicles
Chevrolet TahoeFord ExplorerHyundai PalisadeHonda Pilot
Related Codes
More Exhaust Codes
Frequently Asked Questions
Minor exhaust codes may not affect immediate drivability, but exhaust leaks can allow harmful gases into the cabin. Have exhaust issues inspected promptly for safety reasons.