Ok so today I hopped in my pickup and it was running fine. Would hit full boost with no issues. A little while later I hopped in it to go somewhere and had a really weird problem happen. It runs like usual until it hits 30 psi of boost. Right at 30 psi it drops boost to like 2 psi and doesn't hardly accelerate. It acts like it defuels. I don't suspect it to be a wastegate problem because my wastegate is wired shut. Has been for a long time. Wire is tight and so is the turbo. All I can think is maybe the diaphragm in the afc housing split. Please help

 

It could be the diaphram, can you take it apart and check?

 

Yea I'm going to take it apart soon. Hopefully this week. Whatever is causing it it feels like it's defueling. Very frustrating when I'm on the interstate