How do you know when it is time to replace your exhaust? If I barely touch the throttle, I get a deep hum from the exhaust, like it is backed up. Stomp on the gas and just sounds like slow take off with little power then it takes off. 208000 miles.

 

Its possible your cats are stopping up. At your mileage you're good for cats and O2 sensors

 

Take it to an exhaust shop for an inspection.

 

CATs