Turbo help

hey guys i have a stock b18b1 turbo motor and just recently when i romp on it first gear is fine but after its like its cutting off at 4500 or 5000 rpm. it never did that before and it use to run like a champ. can anyone please tell me whats going on? thanks gurus.

have you shecked your spark plugs? or §§§§§ yet? that would be a good place to start. and what boost level is this happening? stock map reads to 11psi give a lil.

thanks for the reply but i havent gotten a chance to look and this is happening at 8psi. it ran fine before but its like im losing power now

when was the last time you changed your plugs? might want to try this first.