2000 gtp bogs when builds boost

Hello ,
I have recently bought a 2000 Grand Prix gtp sedan it has the 3.8 series 2 supercharged I believe it's the m90 supercharger when I bought the car I replaced tie rod ends gas tank fuel filter plugs ( ac delco professionals) and plug wires ( duralast ) plastic elbows for coolant Water pump harmonic balancer and did and ac bypass because it had locked up on me and in doing so ruined the harmonic balancer I run nothing but 93 octane fuel but I'll get to the point when I had bought the car it sat for a year and It had no problems building boost that seemed evident anyways but not when I build boost there is a loss of power like a miss if i go to wot and hold it while it's doing this the ses light will come on and flash at me I've tried to figure it out and it has me stumped any help would be amazing

Thanks in advance! Oh and it threw a code not to long ago egr malfunction

Flashing SES means a severe misfire. You need to check over your plug and wire install. I managed to break one of the plugs on the backside when I did my plug/wire change.