so I hooked up my MPVI2 pro to my wideband o2 sensor. it worked perfect on my first test drive but every since then I haven't been able to get it to read anything at all. It was set on the red wire when it stopped working, so I re-inserted it into my channel log using the blue wire and hooked it up, neither one will read it at all. I didn't change anything at all from my first run so why did it work then but not work now?