F150 check engine light came on yesterday. Did a scan with Torque Pro and P0420 Bank 1 came up. Looking though whatever I can see on the app the 02 sensors seemed to be operating okay. The offending ratio was barely out of range. Heat gun showed hotter behind the cat but it was hard to get good readings in the driveway with the position of the cat and it was at idle since I didn't have an extra body. Getting under the other side I could hear what sounded like a small leak. Power and economy have not changed. How likely is the leak the culprit? Oddly, I also just got the truck back yesterday from having the speed sensor recall done, and had them look at an airbag issue. The computer was reset it appears. Could the software update have changed the acceptable range?