trouble with cutting out in 1st and 2nd

[DSM_brother2]

i got the car tuned, and we realized the cat was clogged. so i hollowed it out and now in 1st and 2nd it dies out before redline which feels like its lost fuel. and in 3rd it seems steady, does this have to do with the tune? i also noticed the boost was creeping really high, passed 20psi on a s16g with the mbc turned all the way down. thanks for help in advance.