It matches up perfectly with the factory exhaust. I don't know anything about FSWerks exhaust. If your FSWerks matches directly to the stock header/cat assembly then you should have no problem.are there any other modifications needed to be made to run this header? Example; i have an fswerks exhaust, can I bolt this on or will custom work need to be done for proper install?
No and I used the factory sensors: The upstream went in just like factory. On the downstream sensor I added an extension (included) and a couple of washers so that sensor is not directly exposed to the exhaust gas as it flows by.Did you get any check engine lights while running it?