Operation CHARM: Car repair manuals for everyone.

Air/Fuel Mixture: Testing and Inspection

INSPECT 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. Sustain the engine speed at 2,500 rpm for approx. 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 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 the regulations, troubleshoot in the order given.
1 Check the heated oxygen sensor operation.





2 See the table for possible causes, then inspect and correct the applicable causes if necessary.