Air/Fuel Mixture: 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 systems, etc. should be properly connected.

- MFI system wiring connectors fully plugged in.
- Ignition timing set 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 doing 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 according to the table above.
- Check heated oxygen sensor operation.
- Check and correct the cause if necessary.