Would this effect the readings. I have the Edge/Attuide, but I dont belive egt reading on the display are correct, so I would like to wire in my auto meter gauage, and compair the two. I tried to unhook one and run the other, but my short term memery in not that good to rember what the other gauage said

 

Or if you had a couple buddies in your area and wanted to check your pyro's for accuracy on occasion you could go this rout. Check out this link from Genos!
pyro tester

 

You can run 2 gauges from a single probe with accurate results BUT you need to use thermocouple extension wire to connect to the 2nd gauge. If you just run regular copper wire to the 2nd gauge it will be inaccurate because the dissimilar metals (copper to thermocouple wire) will form a 2nd thermocouple and the 2nd gauge will read inaccurately.

If you connect something like a turbo temperature cool down module you can use regular wire because you are only looking for a "relative" (and repeatable) reading on the module not an "absolute" (accurate) reading.