Any assistance or ideas for the following would be greatly appreciated.

I purchased BBK’s 2.5” mid pipe replacement, no cats version, with X pipe. I also purchased BBK's MIL eliminators. One of my catalytic convertors went so it seemed like a good solution. After installing the mid pipe & MIL, my car is now very loud and rasping very badly above 2500+ RPM. It sounds like a bag of ****.  There is definitely something going (more than just the loudness) on as when I punch it, it’s feels likes it’s “gasping/hesitating”. Could the backpressure be reduced to much due to the Magnapakcs plus the mid pipe?

I was thinking of removing the Magnapack glass packs from the catback and replacing them with Flowmasters. I’m hoping this will reduce the sound and solve the problem as everything was fine prior to removing the old midpipe with cats.
Thanks!