Air/Fuel Mixture: Testing and Inspection
CHECK CO/HCHINT: This check is used only to determine whether or not the idle CO/HC complies with regulations.
a. Start the engine.
b. Maintain the engine at 2,500 rpm for approximately 180 seconds.
c. Insert a CO/HC meter testing probe at least 40 cm (1.3 ft.) into the tailpipe during idling.
d. Check CO/HC concentration at idle and/or 2,500 rpm.
HINT:
^ Complete the measurement within 3 minutes.
^ Check regulations in your area when performing 2 mode CO/HC concentration testing (engine check at both idle speed and at 2,500 rpm).
e. If the CO/HC concentration does not comply with regulations, perform troubleshooting in the order given.
1 Check the heated oxygen sensor operation.
2 Refer to table for possible causes, and then inspect and repair.