My son has a 2007 Harley Davidson with a Whipple supercharger.

recently he had a custom duel exhaust installed on the truck (from the converters back) NO Muffler.

About a month later his exhaust has gotten louder BUT just on one side(Bank 2)
The other side still has the same tone as it had after exhaust work.

Trying to trouble shoot what thew problem could be.
So far we ran seafoam through the vaccum lines, and added some to gas tank.
cleaned all 4 o2 sensors
cleaned MAF

Not sure where else to go.


Any help here?

 

I assume that no mufflers also includes no glasspacks. The only thing that I can think of is a cat problem.

 

One of the manifolds could be leaking ?

 

I'm assuming no crossover in the duals? We'll need to work on that. For now, tap the cats and see if there is anything that rattles in them. The honeycomb might have degraded, especially if they welded really close to them.