Like the title says, I have a 1994 OBS Powerstroke and I am getting a CEL every once in a while. When I get it, it comes on and stays on,but if I shut the truck off, the light is out until the next time it gets whatever error. The problem I am having is I can't seem to read the code with my torque app. when I plug into the plug by the glove box, and I tell it to read codes, it scans, the engine stumbles, almost dies, then smoothes out and the CEL goes out and the scanner doesn't show any codes. Anyone have any clue which direction I need to go?