The connection pipes will come standard with the headers and will allow you to fit the headers to your factory H-pipe. It will require you to cut the front portion of your factory H-pipe off in order to clamp the connection pipes in place. This header package will include new Cometic exhaust manifold gaskets, (2) 2.5", and (2) 3" band clamps to complete the installation. The 2001-2004 vehicles will not require a new oil dipstick, tube, and bolt for installation since they received the required items from the factory. You will need to have your computer tuned to turn off the rear O2 sensors since they will be removed for installation. If the ECM is not tuned for the rear O2 sensors, you will have a "service engine soon" light. The front O2 sensor harnesses will have to be extended to accommodate the new location of the O2 bung on the long tube headers. You have the option of including these plug-and-play harness extensions with your order.