Air/Fuel Mixture: Testing and Inspection

INSPECT CO/HC

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

a. Start engine.
b. Hold the engine at 2,500 rpm for approximately 180 seconds





c. Insert CO/HC meter testing probe at least 40 cm (1.3 ft) into tailpipe during idling.
d. Immediately check CO/HC concentration at idle and/or 2,500 rpm.

HINT:
^ Complete the measuring within 3 minutes.
^ 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 the heated oxygen sensor operation.





2. See the table for possible causes, then inspect and correct the applicable causes if necessary.