[combatbmw]

by the mufflers, should be two black hoses.. these hoses own and close the stock valves for noise reduction.

I know the system you have, come w/and w/out valves.

Not sure if the non-valved system has something to plug into, or if you have the valves if they people who installed it plugged in those lines to your new system.

there are two, one by both mufflers. Black vacuum line, that connects to the valve on the mufflers that open and close the valves.

google it, should find plenty of images. If you took your car to a non bmw shop they probably didnt plug in the vacuum lines and thats why you are having issues, cause now you have a leak.. I had the same issue you lose like all your boost.