Hot Swaps

Ok so lets start at the beginning. 03 audi a4 k03 stock tune.

Car ran great at 10psi wanted to do some simple upgrades to motor get a little more power. I purchased a new cold air intake and air box. Installed and ran great same averaging same 10psi. I wasnt happy with the hoses. Thought i was losing some boost so i redid the hoses off of the intake. Focused on the DV hose going into the intake i re sealed and made sure it was sealed right. First run after adjustment out of no place boost was up to 15-17 psi. Very surprised. Pulled hard fist few gears.Problem #1 Than the DV started making a abnormal sound blowing off very sloppy. #2 boost spikes to 15-17 than drops off as if i let off the gas even though i didnt. While still on the throttle boost will begin to rise and fall all by itself without letting off gas. #3 if i continue to do so i lose boost all together and cant get anything more than 3-5 pounds and traction control light comes on for a second. This is a stock DV we are talking about.

Need someone who knows there stuff to confirm my theory.

Boost spikes to much pressure for Stock DV to handle damaging it. Unable to hold boost properly and causing a major leak limp mode activates. only allowing 3-5psi. Replacing DV with ARP r1 DV should do the trick?

Reasoning to believe it is DV besides the sound is if i ride around and keep it under 10psi holds boost enough to not activate limp mode. Or if as soon as i hit 15-17psi release the throttle and dump boost it doesnt go into limp mode. Sound about right?

Lastly did a cold air intake really cause that significant of an improvement to go from 10 pounds to 15 or is something else wrong with the car? Please Help feel free to share ideas could use other opinions. Please HELP.