I have this issue where when ever I get up to speed during only 1st and 2nd gear around 2-3k rpms. I notice subtle vibration/sound coming from my passenger floor panel area. I am hoping its not my chain tensioner making the sounds because i don't notice it during start up and its not very loud either. I checked under my car and my y pipe shielding is somewhat damaged from all the scraping so I'm thinking maybe that could be a possible answer. Was also wondering if it could be my cats because its near my passenger floor panel area. Are there symptoms of a chain tensioner going bad and need replacing? I will post pictures of my Y pipe soon.

 

 

From all that damage on the flex/bellows of the exhaust I'm going to guess you have an exhaust rattle somewhere that you're feeling.

The timing chain is up near the radiator, strongly doubt this is your issue and I've never even seen one cause a vibration issue unless it was literally grenading itself.

 

The nuts and bolts holding the heat shields are notorious for rusting out.

Check for loose clamps.