QUICK UPDATE for everyone! I solved the problem! I finally got around to trying to check the waste gate this weekend. The hasp that grabs onto the wastegate flapper was almost oval instead of round anymore. It added alot of slop in the setup. I removed the hasp and added 1 turn of preload. Im getting exactly 19psi peak and tapering down to about 17psi! So happy this fixed it! I have a new waste gate i will be replacing this one with eventually. I took pics so i will post them later! Might help someone else in the future with similar problems!

 

Woohoo. Called it. 😀

Glad you found the problem and thanks for posting the solution, for all the people that find this thread via search.