I have the SPA EGT gauge, by the way, love these gauges. Sometimes when I push the red button to find out my highest reading, the numbers read 1832 or 1810. Then I have to rezero the gauge again so I can get the proper high temperature readout. This might be good for one or maybe three days, there is just no rhyme or reason for this. I called SPA, they think when I shut the truck off, it vibrates a little bit, therefore giving me that goofy reading. Has anybody else experienced this glitch? I was sent a new black box, that didn't work. The gauge works fine so probably don't need a new gauge which they offered to send me free of charge. I know there is alot of you guys out there with this gauge in your truck. Am I the only one with this freaky phenomanan?