Honestly I would not mess with a "valve management system". It's just a butterfly valve, likely electronically operated, that is installed in the exhaust pipes. It will be a big restriction in your exhaust. Your best solution, and probably the cheapest, would be to install a muffler in lieu of the x-pipe. Don't get hung up on "I've already spent this money and want to salvage it". This thinking often leads to even worse decisions down the road. Fixing it the right way is the only way.