this catback is supposed to go from the stock 2.5" pipe to 3". i have already put on a 2.5" to 3" y pipe that leads to a si/so 3" flowmaster dumped before the axle. i want to switch to the magnaflow. since i already have the 3" pipe, will this cause a problem with the install of the magnaflow supplied pipe? does it use some sort of reducer that is already on the pipe, or installed seperately?

also, is the tip already welded on? i would like to have a dual exit tip instead of the single one.

thanks for the information