Air/Fuel Mixture: Testing and Inspection
INSPECT CO/HCHINT: This check is used only to determine whether or not the idle CO/HC complies with regulations.
(a) Start the engine.
(b) Keep the engine speed at 2500 rpm for approximately 180 seconds.
(c) Insert the CO/HC meter testing probe at least 40 cm (1.3 ft.) into the tailpipe during idling.
(d) Immediately check CO/HC concentration at idle and/or 2500 rpm.
HINT: When performing the 2 mode (2500 rpm and idle) test, follow the measurement order prescribed by the applicable local regulations.
(e) If the CO/HC concentration does not comply with regulations, troubleshoot in the order given below.
(1) Check the A/F sensor and heated oxygen sensor operation.
(2) See the table for possible causes, and then inspect and correct the applicable causes if necessary.
