Emission Control Systems: Testing and Inspection

HINT: This check is used only to determine whether or not the idle CO/HC complies with regulations.

1. INITIAL CONDITIONS.
- Engine at normal operating temperature
- Air cleaner installed
- All pipes and hoses of air induction system connected
- All accessories switched OFF
- All vacuum lines properly connected

HINT: All vacuum hoses for EGR system, etc. should be properly connected.

- SFI system wiring connectors fully plugged
- Ignition timing check correctly
- Transmission in neutral position
- Tachometer and CO/HC meter calibrated by hand
2. START ENGINE.
3. RACE ENGINE AT 2,500 RPM FOR APPROX. 180 SECONDS.





4. INSERT CO/HC METER TESTING PROBE AT LEAST 40 cm (1.3 ft) INTO TAILPIPE DURING IDLING
5. IMMEDIATELY CHECK CO/HC CONCENTRATION AT IDLE AND/OR 2,500 RPM

HINT: When performing the 2 mode (2,500 rpm and idle) test, follow the measurement order prescribed by the applicable local regulations.

Troubleshooting
If the CO/HC concentration does not comply with regulations, troubleshoot in the order given below.
- Check heated oxygen sensors operation.
- See the table below for possible causes, and then inspect and correct the applicable causes if necessary.