Wear & Installation: Worn or leaking flexible tubing is a common noise source and is relatively easy to replace.

The service life of flexible tubing can be improved if it is installed in a relaxed position. Sending, stretching and compressing all reduce life because they limit the tubing's ability to absorb the vibration and thermal expansion.

Good Support: The entire exhaust system should be well supported. 

This will reduce the noise generated by the exhaust pipes and the muffler shell. Care must be taken to isolate engine vibration away from the exhaust system, and to provide for expansion when the system is hot.

Additional Components: Addition of a Universal Resonator in the system will generally reduce the exhaust noise level from 3 to 6 dBA. Packed stacks would reduce the noise level 3 to 4 dBA. Both items have a minimal effect on engine backpressure.

Double Up: Change from a single to a dual system. For maximum benefit, different mufflers are usually recommended. Lower system backpressure is generally an additional benefit of dual systems.

Adjust Your Aim: On horizontal exhaust systems, the tail spouts should be pointed towards the center of the vehicle. This reduces the noise reflected off of the road surface.

On vertical systems, straight stacks will cause lower meter readings than curved stacks will. Straight stacks direct the noise upward, where as curved stacks direct the noise towards the meter.