Boost Issues At 15 Psi Any Idea?

[MIKESGN]

I Recently Installed A Te 44 Turbo From Limit Eng.
I Have A Terry H. Down Pipe With All The Usuall Goodies
And Since I Installed The Turbo , It's Like A Shuttering Feeling You See The Needle On The Boost Gauge Goes Back And Forth From 14 Psi To 18-19 Psi Very Quickly And You Can Feel It But Is Fine All The Way Up To 14 Psi And Once It Starts Doing It You Let Off Of It Slightly And Step On It Again And Its Fine
I Got The Turbo From Another Turbobuick Member And Said That It Had A Smaller Wastegate Hole To Fit Any Downpipe?
I Have A Feeling Its My Problem But Any Sugg. Would Be Appreciated

 

[suicide six]

Sounds as if wastegate puck is boucing on seat.

 

[suicide six]

Might want to check wastegate linkage in down pipe as well,may be sticking. Wye tubes may be leaking at wastegate also.

 

[Mad_Trbo]

Might want to get that checked and corrected quicly the surge factor can eat the turbo if it continues.