Howdy folks, I have a 2013 Express with a 4.3. I recently experienced a couple of episodes of stalling, and then rough running on restart. Both occurred when I put the van in reverse, to back up to a bay door. Had been running fine before then, and when I started back up and drove out in drive, everything's fine again. Intermittent fault in a knock sensor already had the light on for over a week ( those sensors are a labor intensive fix, I planned to get to it as soon as I had time ) but I did another code read, and bank 2, number 2 O2 sensor had thrown pretty much every trouble code it could. My question is, could the downstream sensor cause the stalling/ rough run, especially only in reverse? I know that in the past, downstream sensors did little or nothing to affect computer adjustments. But had this changed by 2013? Or, could all this be the symptoms of a wire harness or ECM problem?