What is an ADD?
http://www.cumminsforum.com/articles/articles/46/1/What-is-an-ADD/Page1.html
By Diesel Minded
Published on 04/3/2007

2002

2001

1998.5-2000
This simple plug-in
device allows you to get an additional 10% horsepower and torque from
your engine! Add it with injectors for a super combination! When
using the ADD with boxes that have a MAP Sensor provision, always plug
the ADD directly into the MAP Sensor, then plug the box harness to the
ADD. To explain it simply: The ADD has a microprocessor that acts as a
electronic voltage regulator, thus never allowing the engine computer
to see an over-boost signal.
Thanks To www.haisleymachine.com/