Check Engine Light - What do these codes mean?

[NJExplorerFan]

I'm trying to figure out what codes I currently have pending on my '97 SOHC 4.0L V6 Explorer. I ran a scan a few moments ago and came up with the following 2 codes:

P0420 - Catalyst Efficiency Below Threshold, Bank 1
P0430 - Catalyst Efficiency Below Threshold, Bank 2

Any idea what this could mean? I thought maybe I needed a new catalytic converter, but maybe it's something else? How can I narrow this down as to my exact problem? Are there any other scanners out there that can break this down further (ie. Ford dealer)?

 

[Scotty J.]

On a hunch, I pasted the code into google and got THIS

 

[jremington59]

Turdle has a couple good threads on that here.

His suggestion was to switch the back o2 sensors, reset the computer and see if it throws a code again for the opposite side. If it does you know the sensor is bad.