Download Porsche 996 Twin Turbo Full Maxflo Exhaust System, Air Intake & ECU Installation – 996 Twin Turbo Maxflo Mufflers *You DO NOT need to remove the rear bumper to do a muffler installation. 1. Safely jack up as per Porsche owner’s manual and always use jack stands. First remove the factory tips from the car so you do not hurt the bumper when removing the muffler. Spray some WD40 or lubricant on all the connection bolts to make the hardware come off easier. The tips are held on by a 13mm bolt on the bottom side. 2. Loosen the 4 13mm nuts at the Turbo and Catalytic converter connection and also remove the bolts on the band straps that hold the muffler to the bracket. 3. Once all the bolts are off, pull the muffler away from the turbos and it will sag down a bit. Once it sags enough to where you can reach the two oxygen sensors, use a 22mm open end wrench and remove those, but make sure you label which one was before and after the catalytic converter. They need to be put back in the same position that they were in. This will now allow you to take the entire muffler off the car. 4. Install the new Sport cats to the Turbo with the factory hardware but keep them loose when doing this. Make sure to reinstall the oxygen sensors back in the necessary positions before installing the mufflers. 5. Once the cats are installed loosely, slide the large band straps over each muffler and leave loose to enable them to slide over mounting brackets. Install each muffler one by one by using the 2.50” V Band clamps provided for the Muffler to Cat connection.