Air/Fuel Mixture: Testing and Inspection
CO/HCCHECK CO/HC
HINT: 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 below.
(1) Check the heated oxygen sensor operation.
(2) See the table below for possible causes, and then inspect and repair.
