Yea I heard about the unison ring getting carboned up so I like to let her eat a few times on short trips and pass the little ricers good n fast on highway trips. Thats why I didnt think it was the unison ring. Is the PCM update what makes it sound like a jet at high idle? I ended up unplugging the EBP sensor and it stopped the turbo bark and power cutting out. Any idea on how/why the EBP tube gets caked up?
Since Jasper didn't answer your question .......... lol
Probably many things can plug the EBP, but poor combustion is a common cause.
Injector issues, EGR issues, turbo issues, etc., even tuning can cause excess carbon. Biased sensors also, like IAT2, MAP, etc.
I like to watch fuel economy as a rough indication of combustion efficiency. I also watch EBP, MAP, and Baro at KOEO to verify they all read the same.
As far as the unison ring goes, carbon and rust are common issues. At least a stainless unison ring can help w/ the rust.