I put a turbo on my truck this weekend, and I'm finishing everything up. I've done all of this before as I have a turbo C5 that I built/tuned. I added pins to 47, and 55 on the blue (C1) connector because I've read conflicting reports of which pin is for the EGR signal on a 2003 Silverado. After I got everything hooked up I upgraded to a 2 bar os, and my "EGR Enable/Disable" option disappeared. Before the 2 bar os update I had the EGR Enable/Disable option; the stock file has it still. After the 2 bar update it went away, and I have no way to enable EGR to log voltage/wideband. In the stock file the EGR was disabled as my truck didn't come with EGR, so I enabled it, flashed it back to stock, and re-did the 2 bar os from the stock file with EGR enabled. This is driving me insane. I've got a 99 Silverado that I put a 2 bar OS on with no problems. The EGR is still there. My C5 didn't come with EGR, and the option is still there. What am I doing wrong on the 03 Silverado?