ok where to start.... so i was driving today and my car started making a loud whistling sound like compressor surge. it only does it under full boost and then it starts to lose boost. everything is fine under normal driving conditions. i am pretty sure my exhaust is leaking where my downpipe meets my catback, and i wasnt able to check but im pretty sure i lost a bolt or something from somewhere because i heard a metal on metal klunk before this all started. im honestly lost at this point without being able to get under my car being that its raining and dark and all.

any info experience please any input would be helpful