2010 Chevrolet Impala - new rumble

Mechanic told Me catalytic converter was okay. I had everything else put in new from the Cat back . Now the car is louder and very noticeable. Even has a rumbling sound when starting out. What could be causing this.


As posted above, the exhaust noise you are hearing is probably just how the new muffler sounds. Are you able to tell where the noise is coming from? If it sound like it is from further toward the front of the car, ask you shop to double check for an exhaust system leak. That sort of leak could be anywhere between the engine and the tailpipe. Common exhaust leak locations are in the exhaust manifold/flexible-pipe section area.

Exhaust leaks often result in a diagnostic code. Is there one store in computer memory, either pending or active?

Probably didn’t install the Resonator Pipe

The resonator is a complement to the muffler in that it removes high-pitched noises along with annoying hums and buzzes . It creates a smoother exhaust note, but doesn’t affect volume. The resonator is designed to eliminate sounds at a particular frequency which bounce off the inside of the device canceling each other.

The best sounding Lexus SUV I ever heard was when a lady came in with a little louder then normal exhaust and said nobody (obviously she didn’t ask the right people lol) knew why…
I peaked under the vehicle and noticed the resonator pipe was missing… Everyone at the shop liked the sound also…