Air/Fuel Mixture: Testing and Inspection

CO/HC
INSPECT CO/HC

HINT: This check determines whether or not the idle CO/HC complies with regulations.

(a) Start the engine.
(b) Keep the engine speed at 2,500 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 2,500 rpm.

HINT:
^ 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 below.

(1) Check the A/F sensor and heated oxygen sensor operation.
(2) See the table below for possible causes, then inspect and correct the applicable causes if necessary.