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 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 Exhaust Gas Recirculation (EGR) systems, etc. should be properly connected.

(f) Sequential Multiport Fuel Injection (SFI) system wiring connectors fully plugged.
(g) Ignition timing check 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 concentration 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.





Troubleshooting
If the CO/HC concentration does not comply with regulations, perform troubleshooting in the order shown in the image.
(a) Check oxygen sensor operation.
(b) See the chart for possible causes, and then inspect and correct the applicable causes if necessary.