Air/Fuel Mixture: Testing and Inspection

INSPECT CO/HC
a. Start the engine.
b. Run 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 2,500 rpm.

HINT: When doing the 2 mode (with the engine is in the idle and 2,500 rpm) test, these procedures may vary according to local rules.

e. 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, and then inspect the applicable causes and repair it if necessary.