2002 Toyota R4V4 fault codes P0420 and P0430

Vehicle Question:

I own a 2002 Toyota R4V4 and using my all-In-One Scanner, I get two fault codes: P0420 (Catalyst effeciency low bank #1) and P0430 (Catalyst low bank #2). Watching the rear oxygen sensor reading on the scanner,it looks normal.Also,the reading was switching back and forth at idle.However, after I reset the codes, the codes came back.Any suggestion?

Vehicle engine code advice:

There is a TSB regarding these codes (Toyota service bulletin #EG010-02 explains the correction's for these codes) and it calls for upgrading or reflashing of your engine computer by the dealer. This service is offered FREE and all you need is book an appointment.

Your rear oxygen reading is not supposed to switch at idle and that would indicate a CAT failure.Usually, the oxygen reading will osciliate only after 1500 rpm but not on idle.Have the dealer upgrade the computer first and followed that by CAT replacement which is covered under 8 yrs or 80 miles warranty.

Note:

Make sure you have done your regular maintenance like plugs and filter change before you see the dealer.