I'm having a similar problem with my all stock IX MR.
1-1.1 bar then tapers off. It used to flash to 1.3 -1.4 bar then taper.
I'll be making a leak tester this week.

Interested in knowing if there's a test to check the WG actuator.

Shoe

 

I currently have bigger issues but i experienced the same thing. peaked at 17-18 then tapered to 15-16. Boosts tests didnt really show much so i got a boost controller and it ran good till a few weeks ago when i blew an intercooler, threw a cat code and started boosting wastegate pressure as well as ran lean. Then yesterday she shut down on me on the freeway, cranks but wont start. Thinking fried ecu or i tripped the immobilzer last place i want to go is the dealer. Any ideas?

 

were you boosting when it happened? do you still have the stock ECU, if you blew off IC piping it'll cause this too I had this happen. It was extremely hard to see the piping looked connected but it wasn't. An AEM will keep the car running, but the Stock ECU can't adjust for it, it requires the Turbo to run.

 

EvoM guru's solved my issue, blown fuse feeling really dumb. I guess in my rage I didn't check the fuses close enough. Well now I'm back to the original issue of lean conditions and 13 lbs of boost which I'm hoping a boost leak test will solve.

 

what fuse was it?

 

well i'm ordering spark tech's non CDi COP today. i think that will help the boosting problems. it will definately cut out the missfiring. there's no question that the coils are going bad on the car. the only question is what effect that has on the car boosting. when i changed the wires and plugs at 120k i saw a .5-1psi increase in max boost for a while. then i started getting the missfire codes and the high rpm missfire, and after that i noticed my peak boost had fallen off a bit. it just seems like those two are related. once i get the COP installed i'll post results. i think this should help solve my problem though. anyone else care to chime in?