Ok, I did not expect it to be a 07 and have that code. I did search for bulletins and there is one about an exhaust leak that may be setting that code. Below is a copy. Also, I am from Canada so I am not sure what you mean by an "R" title.
#PIP4218A: DTC P2097 P2099 P2096 P2098 P0420 P0430 - keywords code DTC exhaust leak LY7 MIL SES - (Nov 12, 2007)
This PI was superseded to update model years. Please discard PIP4218.
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
The customer may have a concern of the MIL being illuminated. The vehicle may a DTC P2097, P2099. P2096, P2098, P0420 or P0430
If following eSI diagnostics does not correct concern then this may be an exhaust leak. This leak may be very small and hard to locate. The ultrasonic leak detector J-41416 may assist in finding the leak. Be sure to check the seal between the exhaust pipe and converter. Also the welds around the HO2 sensor fitting may have pinholes.
IT could take 3 drive cycles to set the code. Below is some information on the code.
Important: A new converter with less than 100 miles on it may set DTC P0420 or P0430 due to out-gassing of the internal matting. Operating the vehicle at highway speeds for approximately 1 hour may correct the condition.
A 3-way catalytic converter (TWC) controls emissions by converting hydrocarbons (HC) and carbon monoxide (CO) into carbon dioxide (CO2), and oxides of nitrogen (NOx) into nitrogen. The TWC also stores oxygen. When the listed idle conditions follow the listed driving conditions, the Catalyst System Efficiency test will run. The engine control module (ECM) monitors this oxygen storage capacity by comparing the pre and post-catalyst oxygen sensor signals while adding and subtracting fuel during specific idle conditions. The ECM compares the pre and post-catalyst-oxygen sensor signals to determine if the oxygen storage capacity of the catalyst is degraded.
Conditions for Running the DTC