D&D Exhaust 579Z-31F Black Fat Cat 2 into 1 Exhaust for 1984-2017 Softail Models
2:1 Fat Cat is a stepped header system at the head is 1 5/8″ to 1 3/4″ to 1 7/8″ at collector and 2 1/2″ where the muffler goes to the header. All full systems are equipped with heat shields, bolt kit, brackets and baffles. You should purchase and install new exhaust gaskets, flanges are already included. Each exhaust system is designed and dyno tested. Every pipe is designed to increase low-end torque and horsepower. Performance increases are about 8 to 10 percent with the proper tune on the bike.
It also comes with both 18mm and 12mm O2 bungs so it can be used with an auto tune module such as the Thundermax Auto Tune.