hello i have just installed some greddy guages on my 88 supra. they were not new but they did work on another supra like mine. i was having trouble with the EGT guage. its installed on the car and seems to work great when the car is on but when i turn the car off the guage shoots up instead of down and seems to get stuck there even after i turn the car on again. if i drive the car for some time and then tap the guage the needle then drops down again and continues to function normally until i turn off the car again. i tried to locate the problem by simply removing the sensor from exhaust and turning on and off the car to see if it would malfunction but it didnt. when the sensor was out of the exhaust the guage seemed to function normally. i did install the sensor by welding a nut to the downpipe and then just screwing the sensor on to that with just the sensor itself penetrating the downpipe. i have found a way around the problem by just simply unplugging the sensor from the guage before shutting the car off and then reconnecting it before i start the car. i would obviously prefer to not have to do this all so my question is whether the sensor might be going bad or is it that the whole probe itself needs to be inside the downpipe for some reason? any advice would be greatly apreciated
