Any luck on this? Is there a way to test for a stuck wastegate that I can perform myself? I can only build about 20-22 psi of boost, and the turbo lacks the distinct whistle it used to have. Truck only has 80,000 miles and with the edge on level 3, it smokes more than it did a year ago at the same level. Stock turbo, manual trans. Also seems sluggish from idle to about 2000 rpm. It had a thermostat stuck open for awhile, but I am not sure how long as it never got cold enough for it to be noticeable to me.
Fixed that, but it's still not right even when 190 degrees.