Originally Posted by windstar99

First thing first. Don't automatically think the Cat is gone. When this type of code appears, it's beyond a "backyard" mechanic diagnosis. You don't want to throw good money at bad and replace the cats and it turned out to be a sensor or wiring issue.

The code is telling you that the sensor Bank 1 Stream 2, downstream of the cat (after), is reading out of Spec. There is a posibiltiy that the upstream sensor is bad, causing a rich mixture on one bank or the other. Thus causing the downstream sensor to read out of bounds also.

What needs to be done at your local garage or Dealer, is they can drive the vehicle and monitor what each O2 sensor is doing in real time. Also they can see is it's also a wiring issue. They will let you know for sure if it's the sensors or the cat. My hunch is the sensor. If it was the cat, there would be a greater issue of driveability.

Lastly, O2 Sensors are a lot like spark plugs. They don't last forever. They only have a service life of about 60,000 miles (100,000 kms) Thus, they will wear out even if there is nothing wrong with your cats.

I have a 2002 Supercrew with 145,000 Kms. I have already replaced 2 of them.