I bought a used skunk2 catless dp from here. I didn't see any damage on the DP what so ever.. I bought the Invidia N1 exhaust new.. After installing it, I am hearing what sounds like an exhaust leak. I installed all new gaskets except for the one that connects the DP to the motor (I used the OEM gaskets). Now I went under the car three times to make sure everything is tight, I found a few bolts that weren't tight so I tightened them down. I turn the car on and........ I still here it.. Any help would be greatly appreciated.