I know the directions are to install the temp probe into the rear chamber before the turbo. On my Excursion in my sig I could not get a drill to the rear one so I put my EGT probe into the front chamber before the turbo. My truck and the Excursion in my sig are set up similar but the EGT's in my Excursion are always close to 200* hotter. Is the probe location the difference? I should also note that I have a Quazilla Commander reading the EGT's in my Excursion and analog gauges in my truck.

Thanks

 

Probe location, specifically the distance from the flame is the difference. 1/4" can make a difference.

 

By always do you mean even at idle? low boost?

When the wastegate opens it only vents the front three cylinders, that's why it's recommended to tap into the rear chamber, it's the hottest.