exhaust works off of 2 principles.. Backpressure and flow... Backpressure creates torque, flow creates HP, you can argue that all day number wise, but those 2 principles hold fairly true, less flow more hp, less torque. The Pathfinder is tuned for more torque than HP, therefore requires a little more backpressure for the torque, people who add exhausts will notice a little bit of a loss of torque in the gain for HP, since aftermarket exhausts are less restrictive.
the murano is different, its probably tuned more for hp, than torque..
now i could be overanalyzing it, and it was a matter of underbody packaging

but the note above is true
