Maganaflow exhaust - and slow turbo response

[scarm]

I put on a dual - Magnaflow exhaust system - on my 2005 F250 6.0

Also had my catalytic converter removed.

now my truck has lost it's snappyness.

I started out with a Bully Dog power pup downloader - it worked great - it's just the new exhaust took alot of the quickness out of the vehicle.

I'm guessing it has to do with backpressure - but I don't want to replace the magnaflows - is there anything I can do to fix the situation...

Also, I did purchase a Spartan Phalanx tuner - the trucks performance really sucks with that POS - and I can't get the guys at Spartan to reply to my requests for new tunes (It's been since May and I don't even have the third tune that was supposed to come with the unit)