Yes I do not understand why. I don't have a check engine light on and just today put a new downstream O.S. in. I have driven 2 drive cycles 7 min.@ 55mph. and 7 min.@ 45mph. and still the catalyst monitor is incomplete all other monitors are ok and no codes on the OBDll/EOBD. It does show 2 codes in the engine trans. module which are P1210 which I have heard one reply it is a ghost code but someone else told me and I saw it myself could mean excessive fuel rail pressure sensor but I cannot see where it is on the fuel rail and do not see a sensor like that listed anywhere. I have a code reader and it says for the code P1210 no DTC defination found see service manual. In my Haynes manual I can find nothing about this. Can anyone shed some light on this as I am at my wits end and the plates run out in less then a month. I have posted this on Toyota Nation also.

 

The scanner is showing a code not listed for this car but for Ford. Given there is no fuel pressure sensor disregard the code.

If you have the service manual. Try operating the engine based on the Combination Engine Racing Patterns shown for code P420 and your cars emissions, Calif or except Calif.

The link below may also help.

1997 Toyota Camry Monitors Incomplete