With CONSULT

^ The three-way catalyst function has one trip detection logic.

OVERALL FUNCTION CHECK
This procedure can be used for checking the overall function of the three way catalyst. During this check, a Diagnostic Trouble Code (DTC) might not be confirmed.

1) Start engine and warm it up sufficiently.




2) Set "MANU TRIG" and "HI SPEED", then select "FR O2 SENSOR", "RR O2 SENSOR", "FR 02 MNTR", "RR O2 MNTR" in "DATA MONITOR" mode with CONSULT.
3) Touch "RECORD" on CONSULT screen with engine speed held at 2,000 rpm constant under no load.
4) Make sure that the switching frequency between "RICH" and "LEAN" of "RR O2 SENSOR" is very less than that of "FR O2 SENSOR".

Switching frequency ratio =

Rear heated oxygen sensor switching frequency
Front heated oxygen sensor switching frequency

This ratio should be less than 0.40 for A/T models and 0.37 for M/T models.

If the ratio is greater than the above value, the three way catalyst is not operating properly.

NOTE: If the "FR O2 MNTR" does not indicate "RICH" and "LEAN" periodically more than 5 times for 10 seconds at step 3, perform TROUBLE DIAGNOSIS FOR DTC 33 (Front heated oxygen sensor) first.