Without CONSULT

OVERALL FUNCTION CHECK
Instead of performing DTC DETECTING CONDITION, the following method can be used for checking the three way catalyst function. (The "NG" of the OVERALL FUNCTION CHECK means the same as the DTC detection.)
1. Start engine and warm it up sufficiently.




2. Set voltmeters probes between Engine Control Module (ECM) terminals 46 (front oxygen sensor signal) and 43 (engine ground), and ECM terminals 52 (rear heated oxygen sensor signal) and 43 (engine ground).
3. Keep engine speed at 2,000 rpm constant under no load.
4. Make sure that the voltage switching frequency (high & low) between ECM terminals 52 and 43 is very less than that of ECM terminals 46 and 43.

Switching frequency ratio =
Rear heated oxygen sensor voltage switching frequency -over-
Front oxygen sensor voltage switching frequency

This ratio should be less than 0.8.

If the ratio is greater than 0.8, it means three way catalyst does not operate properly.