Hi Jason,
By now you may have noticed that some folks are very sensitive about problems with some turbines...... Dont worry, many other brands have their own problems too.
The problem you have is caused by poor RF suppression on the EGT probe amplifier. This amplifier has to amplify a very small signal 20 - 100mv DC to something the ECU can read. This makes any AC external signal imposed on the leads cause an error if not "shorted". The torroid you used for the cable has the effect of short circuiting the AC (RF from your TX) before it gets to the amplifier. Here is an even easier solution that should have been on the PCB of the ECU. Remove the cover from the EGT probe plug and using the terminal screws that hold the wire, put a disc ceramic capacitor of 10 nanofarads across it. If the problem persist put another one of 1 nanofarad in parrallel with the 10 nF one. If this failes to improve the problem you most probably have to live with it. Let us know what you find.

Turbojet