bgw70

iTrader: (1)

My stock 68k mile 2000 T/A had a P0430 code and no O2 sensor codes. I checked the O2 sensors and they too looked fair. The downstream sensor had some degree of voltage movement which is a bad thing.
I decided to replace the bank2 up and down stream sensors before I replace a cat. The new downstream sensor has a nice straight line on the graph which would be steady voltage.
I purchased the sensors from Rockauto.com for $28 ea.
The new sensors corrected the P0430 code for now.

bgw70

iTrader: (1)

I have now driven several miles with several engine startups and the computer has not detected any faults. The Evap is not a fault but only an incomplete test and should clear soon.
I am now confident the new O2 sensors corrected the P0430 code. Many will say this is rare.

Burken01

iTrader: (88)

Po430 is a cat code

The O2 sensors are fine since they both have to be working to even run the "cat readiness" code and set a p0420-p0430

bgw70

iTrader: (1)

Then why would new O2 sensors clear the fault? Is it not possible to have a sensor that is not functioning properly?

Burken01

iTrader: (88)

not sure...

I was chasing catalyst codes and did research and found out that you need 2 working O2 sensors to even be able to run the cat readiness test.. Then after driving 5-10min if it fails it will throw the car code..

Have you put more miles on the car? No more codes came up?

bgw70

iTrader: (1)

I changed the O2 last Friday and drove the car all weekend and have well over 15 engine cycles and 60 miles or so.

The idle is still smooth and no codes so far.

The replaced the OEM AC Delco sensors with Denso. The drivers side is still has the original sensors.