Tequila: GM techs have strict orders to inspect why there are irregularities when they hook up to your ECM. So if you were having drivability problems and they either found you were using a chip or that there was an abnormal amount of regens they would want to know why. The ECM would likely show sensor problems. If they suspect it is due to using the wrong fuel the tech will take a screen shot of his computer and shoot it off to GM. Then that VIN loses the powertrain warranty. They take these matters very seriously. A quick oil analysis could show high sulfur content. I know that new OTR truckshave a GPS in the ECM. I wonder if the new PU's have the same? Big Brother might be watching!
