Emission Control Systems: Testing and Inspection

INSPECTION

HINT: This check is used only to determine whether or not the idle CO/HO 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.

HINT: All vacuum hoses for Exhaust Gas Recirculation (EGR) system, etc. should be properly connected.

f. SFI system wiring connectors fully plugged.
g. Ignition timing checked 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.
Complete the measuring within 3 minutes.

HINT: 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 in the order given.
1) Check oxygen sensor operation.
2) See the table for possible causes, then inspect and correct the applicable causes if necessary.