Are you using the TEC option with your pipe? Have you tried it with and w/o?I'm most likly going to get the full system but not sure of the TEC opt.

 

I have the stainless system with the TEC. I installed and jetted per instructions with the end cap that it came with (loudest setting). So far so good, I haven't tried the mid level or low level noise end caps yet.
Next I will add k&n filter, jet and needle kit.

 

I've used the endcaps just to see what the difference was. They do make the bike alot quieter. The smallest cap makes less noise than stock on my 400ex.

 

I will eventually, i'm kind of enjoying the sound and vib from the louder set right now. Although I don't think it is annoyingly loud like some other pipes I have heard.