I had a persistent EGT sensor code.
I didnt want to shell out the $300 for a new one.
I took it out, cracked it open to see what it looked like, low and behold, the signal wire coming from the probe into the circuit board had a bad solder joint. The whole thing was filled with a silicone like jelly. I scraped that off with an old toothbrush and fixed the solder joint. Refilled the enclosure with plain old silicone caulk. reinstalled, cleared the old stored code, and voila. No more EGT code.
I hope this can help someone else out.