I had one of those Powertech exhausts from e-Bay installed on my maxima. It is, however too loud at low RPM's, and doesn't do a thing at WOT.

I looked under the car, and the factory resonator is still there.

My question is this... The guy from the muffler shop told me to add a resonator to get rid of the droning at low RPM's, but if I have one installed already, would another one really make a difference?

If this doesn't work, I have a Powertech Muffler for sale...

I think I may install the factory muffler anyway... Who knows.