This sounds very familiar from when Phuong had worked on my car doing an E85 tune. I also had to go back to him to have him fix my tune, not to mention the several emails he sent with a tweaked tune. Similar codes, and similar issues with work not being completely done (hoses falling off, not hitting peak boost, etc). Two months pass by, and guess what...my motor went BOOM. Coincidence due to tune? Maybe...But I was pushing over 400 to the wheels for a good amount of time. One will never know the true cause for me snapping a rod in half.
I don't doubt his intelligence and tuning capabilities, however we all know his cream of the crop lies with EVO's and not the Subaru platform.