On MC produced vehicles, when running catalyst efficiency monitor test using the WDS tester, PID 02S22 will always register 0V when using software version B-9 thru B-11. This condition occurs with 00MY and earlier MC produced vehicles with 6 cylinder engines that utilize PID 02S22 only.
On 01 MY MC produced vehicles, the PID works properly with all versions of software.
When diagnosing code P0420(Fed) or P0431(CA LH) use the NGS tester with Version 9 card when performing Three-Way Catalytic Converter (TWC) Inspection found in the 00 WSM page 01-16-14.
With the release of version B-12 WDS software (Release date Feb 26,01) PID 02S22 will properly display the correct 02 sensor input voltage.