Just had a neat little experience...Got engine noise in your Pathfinder Empeg install all of the sudden? Check the cigarette lighter connection! Apparently the electrical ground wire for the center console, while it does go to the chasis, is connected to multiple accessories in series. My lighter connection came loose and all of the sudden I had major engine noise in my speakers while using the Empeg. I plugged the lighter connection back in, and...instant silence. I imagine that this would apply to many nissan truck models around the 94-96 timeframe.