swathdiver
Full Access Member
You're right, my mistake in that the lines from both the upstream and downstream look similar only while cold, not hot. Your bank 1 is more normal than bank 2 lower sensor, they should both respond to rpm changes.
Is the 93419 the whole enchilada, cats and y-pipe? I installed basically the same thing on mine in February, 51578 for GMT900, and it's working great and my mileage came back after a couple hundred miles as the cats wore in.