Overview
This emissions inspection procedure is designed to help ensure vehicles meet environmental standards by evaluating emissions-related systems including exhaust, fuel, and onboard diagnostics. Regular inspections contribute to cleaner air and vehicle efficiency.
Inspection Components
1. Visual Inspection
- Verify presence and integrity of emissions-related components
- Check for visible smoke or tampering of emission systems
- Ensure fuel cap and emissions label are intact and legible
2. OBD System Check
- Connect scan tool to OBD-II port and verify ECU communication
- Retrieve Diagnostic Trouble Codes (DTCs)
- Check readiness monitors and MIL status
3. Exhaust Gas Analysis
- Conduct emissions measurement for CO, HC, NOx, CO2, and O2
- Use appropriate RPM settings and testing durations
- Compare readings with vehicle-specific standards
4. EVAP and Fuel System Test
- Inspect for leaks in the EVAP system
- Check purge valve, canister, and pressure sensor
- Validate fuel system pressure and injector operation
5. Regulatory Compliance
- Ensure vehicle meets emission requirements for its year/model
- Verify exemption or compliance documentation
- Review past test history and recall actions
Final Certification
Technicians must document results, note failures, and provide certification for vehicles that pass all inspections. Retesting procedures must be followed for non-compliant results.