hey im new to this forum. sorry if i posted this wrong. so i have a 2014 3.7 v6 mustang about 120,000 miles on it and yesterday day i started hearing this weird rattling noise coming from the engine bay.i put the car on a jack and the noise seems to be coming from the drivers side somewhere near the transmission. i drove the car for a bit and it seems to go away when i pick up speed,and other thing that i noticed while i was driving the car is that when i completely floored the gas the car accelerates very slowly compared to how it used too. also the exhaust doesn't sound the same when i press on the gas. today i drove my car to work and the rattling sound went away, but everything else is still there. any idea on what could be wrong?