I need opinions, I own a 6th gen 07 nissan maxima sl 3.5 and i recently made a 4 hour drive from Merced to LA and back almost immediately. Once I was exiting the highway I heard a noise coming from the engine almost as if I was reving it in neutral. Once I advanced again it sounded almost as if it was working harder than it should be for the 20mph I was going. At the same time that I heard the noise the oil pressure light came on but not solid neither flashing more like a flicker. I pulled over and waited a while then I started driving again to get home and it felt as if was in high gears and would struggle when coming to a stop. Since I read in the manual that nissans oil pressure isn't designed to be a slight warning and to contact a mechanic soon I haven't driven it at all. Any thoughts what could be wrong? I got a tune up services on it about a month ago and the engine oil looks good. Help please??

 

It could be a number of things. A shop can check the oil pressure but it sounds to me one or two things, the oil pump or oil gallery gaskets.