On my current set-up, I have three Defi Gauges (Boost, EGT, and Oil Pressure). They all work great, except each time after I wash the car, the EGT's warning light goes off for about a minute with no readings whatsoever on the gauge. If I cover the sensor when I wash the car, on startup, the gauge works perfectly. So, obviously it has something to do with water getting in contact with the sensor. I believe that the sensor is all the way in, but am not so sure -- there are some threads on the actual sensor still showing ...could this be the problem?

Thanks.
-CR

 

Is the sensor in their tightly? with the exhaust manifold heatshield off and the car cold, turn on the car and quickly feel around the egt sensor to see if you can feel air coming out of it.

 

egt sensors are type K thermocouples. the dissimilar metals chromel/alumel junction generate a millivolt(mV) when heated

25C = 1.000mV
850C = 35.313mV

water is shorting out the 2 wire somewhere between the probe and the lead wire

 

I just looked more closely at it after I tried to feel for air (none was escaping), and sure enough, there were two exposed wires that were connected to another two. I believe this is the source of the problem. I will fix it in the morning. Thanks for all ideas everyone.