P0420 Code Questions

[Oleschool]

My truck had P0171 and 172 until I fixed the vacuum leak.Now I have this one.It was there before but went away.I scanned it and the o2S1 was about .790volt at idle while the o2S2 was about .890 volts.These two are consistently about this far apart.(roughly 0.1 volt)Is bank one on the drivers side?Also wheres the best place to buy a replacement catalytic?

[smj999smj]

Bank 1 is the bank that starts with cylinder #1, which would be the right, or passenger side. Try to stick with well established name brands if you purchase an aftermarket converter, like Bosal or Walker. Try Rockauto.com. If you Google "Rockauto discount code," you should be able to find a 5% discount code to use on your order.