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Normally if you have an 02 Sensor problem it would show on the MIL light, however I have a sneaking suspicion that the MIL light is disabled on the Tornado chip (anyone know?) However if you have a problem, then the engine would not be running correctly.
As you seem to have a diagnostic unit can you check the operational mode which should be running closed? if so the 4 sensors and the heaters have passed all the diagnsotic checks.
Alas here the sum of my knowledge ends, so not too helpful I'm afraid.
If you have not seen it, I would browse through
David Poole's Truly Excellent Gems Guide Brian
