That is a very tough place to fix. The only chance to get it is with the pipe on the bench. That material is very difficult to weld.
That is if it's a stock pipe.
90917-06043. The 06076 is behind the second cat. Check that joint as well since it's upstream of the rear sensor.
You want to be sure there are NO leaks in between the sensors.
I had a set of high-performance aftermarket cats on my SRT8 Challenger and It kept tossing cat codes. It ended up being a couple pinhole leaks in the welds. It doesn't take much.