I am thinking thrown rod. Anyone have any ideas??

 

Yes that's definitely a rod knock.

 

Carry a screwdriver with you at all times so when it finally dies you can just remove the plates.

 

Had very similar sound from my 2003 Maxima. Thought same thing....rod knock. Turned out to be the insides of the cat closest to the engine is made up of much harder material. when they break down they will become a large chunk of cat material bouncing around inside the cat.

I disconnected the exhaust, gutted the cats while on the car (not easy to do) put it all back together and TADA!!!! No more noise, no engine rebuild, and the car ran a hell of a lot better!!

Give this a look. Even replace the cats if you don't want to gut them. A lot cheaper than an engine rebuild.....OR TEST PIPES!!!

The lower cat is soft material and guts easily. The upper cat (where the noise is coming from) is much harder material. I used an impact drill with a very long spade bit to reach up into the cat and eat away at the material. Wear a mask and full face shield. Total cost was $5 for long spade bit and about 3 hours of my time.

Should be easier on the G. The Maxima has a transverse mounted engine and it is near impossible to remove the rear cat, so you have to gut that one on the car.

Hope this is the issue with yours rather than a rod knock.