I had my muffler replaced under warranty because there was a leak where it met with the pipe. So they just replaced it with a new muffler. I remember hearing people say that when the car is at idle only one pipe has air flowing through and that one side stays closed at idle and under a low load for more torque and then it opens up. Well on my muffle at idle both pipes have air flowing out of them. Do you think the variable capacity design isnt working on the new muffler? Thanks a lot

 

its nissans variable system thing. its on the maximas as well.

 

Yeahh I understand the system I was just wondering if mine is not working, because at idle air is flowing through both pipes...

 

check with an infiniti tech... maybe DaveB will chime in, i think he knows more about the oem exhaust system

 

Daveb, anyone... ?

 

I checked several G's as they came in this morning. The earlier models only used 1 side at idle then both at upper rpm. The newer ones used both. I had the parts dept look up the mufflers & there is a production date split of 08-2004. That date is also when the sedan switched to the smaller resonator.
So, basically 03 & 04 have the variable muffler, 05 & 06 have a standard muffler with the smaller resonator. I have no idea why they made the change.

I hope this helps.

 

this explains why the 05/06 is louder stock too...

 

i know, it's sooooo sexy in 1st and 2nd.