My left muffler looks like it's about 1.75", my right is around 2.25". There's definitely exhaust coming out of both sides.

 

That probably explains why Dynojet says to disconnect the 02 sensors when attaching the PC.

 

Although the RH muffler is used as the primary muffler, the left muffler also plays an important part in our baffle design. The LH muffler does expel exhaust (although a reduced amount than the right) and the baffle features a unique cone which controls reversion.

 

Actually, the reason is because unless the O2 sensors are bypassed you cannot richen the mixture properly as the EPA mandated O2 sensors will continue to adjust the mixture to 14.7:1 AFR which is way lean.

 

Thanks Jamie for your explanation.

 

Man, I can hardly wait. I just ordered my mufflers, PC V, and A/C from Keith for my 09 Ultra. It will be about 4 days. ARGH!!! It is going to be awesome.

 

So even with the PCV you must disconnect the O2 sensors? Do they stay disconnected all the time or just on initial setup of the PC.

Thanks

 

i do believe that, the only way to use the 02 sensors is if you would use the auto tune from fuel moto or another tuner like thundermax or a couple of other ones..........

 

trust me you WILL have a smile on your face.
the fuel milage will suck for about the first tank or untill you quit twisting the trottle so aggressivly

 

Yep!! all the above here Maybe for more than one tank in my case LOL.
I like the way it runs and I love it's new sound..........the wife loves the sound, she is still waiting on throttle to ease up......she might have to wait awile longer.