I'm not 100% at this point, but, I think the original O2 sensor is still in there. I ran out of daylight before I could find the plug end.
I'm disappointed about the results of the EGR even more so because of how much better the truck is running. Even the inspection guy made a comment of how it sounded different when I pulled up to his shop.
Are Bosch sensors that bad? It's all I have readily available without ordering.