1984-2017 Harley Softail Fat Cat 2:1 Full System


1984-2017 Harley Softail Fat Cat 2:1 Full System

Year: 1984-2017
Make: Harley Davidson
Product Number: 579Z-31 Black 32 Chrome


Retail Price

Systems with Louvered baffles

Chrome $ 799.00     Black $ 949.00

Systems with Perforated Wrapped baffles

Chrome $ 799.00     Black $ 949.00

Part Numbers and Instructions at bottom of bage.


1984-2017 Harley Softail Fat Cat

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.
Best exhaust gaskets to use SE gaskets from Harley
Each exhaust system is designed and dyno tested in our facilities.
Our testing is done with the Harley Tuner's
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.

Louvered baffles are for 80" to Stock103" motors
Perforated Wrapped baffles are for Stage 4 103" to 113" motors
Note: The inter core of the louvered baffle is 2 1/4"
Note: The inter core of the big boar baffle is 2 1/2"

Note: Using Woods cams for best performance use the Perforated Wrapped Baffle


2:1 Low Cat comes with 12mm and 18mm O2 sensor bungs.



Will not fit the 2013-2016 Breakout Softail beacuse of the oil tank.




At idle, the motorbike is deep, boomy
and full of character. Not only does the pipe look good,
it is a wonderfully sounding experience for the rider.
Dave Rash, Pope of Pipe


Note: Blueing and Discoloration
are caused by Improper Tuning
and will not be covered under Warranty


D&D Performance Exhaust Systems

are designed for close course racing applications only.
Not for use on pollution controlled vehicles.

Finish Options:
  • Midnight Black
  • Show Chrome

Cut Options/Additional Images: