I havnt isntalled my mechanical guage yet but the stock seems to be working cuz the truck shut off as soon as the guage dropped and u can see it move as it turned over. I kno their notorious for being spuratic but mine seems to be working plus the red oil light is been on ever since this problem has started. Also the truck doesnt try to start till the pressure builds up on the gauge wich i would assume is let the ip do its job