CO/HC Check

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

1. Initial conditions.
(a) Engine coolant at normal operating temperature.
(b) Air cleaner installed.
(c) All pipes and hoses of air induction system connected.
(d) All accessories switched OFF.
(e) All vacuum lines properly connected.

NOTE: All vacuum hoses for EGR systems, etc. should be properly connected.

(f) Sequential Fuel Injection (SFI) system wiring connectors fully plugged.
(g) Ignition timing set correctly.
(h) Transmission in neutral position.
(i) Tachometer and CO/HC meter calibrated by hand.
2. Start engine.
3. Race engine at 2,500 rpm for approximately 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 concentrations at idle and/or 2,500 RPM.

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

- If the CO/HC concentration does not comply with regulations, troubleshoot according to the table under Diagnosis By Symptom.
Symptom Related Diagnostic Procedures