Air/Fuel Mixture: Testing and Inspection
INSPECT CO/HCa. Start the engine.
b. Race 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 doing the 2 mode (idle and 2,500 rpm) test, these measuring orders are prescribed by the applicable local regulations.
e. If the CO/HC concentration does not comply with regulations, troubleshoot in the order given.
Check heated oxygen sensor operation.
See the table in image for possible causes, and then inspect and correct the applicable causes if necessary.