After the catalytic converter was replaced on our 2000 S70 GLT SE the engines seems to have a deeper, louder, more throaty sound.

The louder exhaust is somewhat irratating.

LP

If everthing is tight and snug, it could be your muffler that is showing its age.

Essential to check for leaks as Klaus indicates. If that does not turn up something, are pipes not rehung properly so something is rubbing against the body somewhere? Also in my case I hit a large rock after which the exhaust got louder. Repeated checks for leaks show nothing (even after 4 years). We concluded an internal baffle in the muffler was broken. Pipe from cat to muffler is visibly bent. We learned to live with it.

Raise the front of the car so that you can slide under it quickly. When the exhaust is completely cold, start the car and immediately check the couplings/joints at the cat for leaks. Be careful, the heat builds rapidly by design.
Also check the area where the tail pipe joins the pipe coming from the converter. This is a pressure fit with a simple clamp. Many times the tail pipe is not pushed forward enough before securing the clamp and a small amount of exhaust will leak out there.

Klaus
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(V♂LV♂s 1995 854T, 1998 V70R)

Come to think about it, the tone of my exhaust did change a bit when I changed my catalytic converter. It became louder with a deeper tone. I was not much that I found it objectionable. As a matter of fact, I like it better because it sounds like a performance car. I attribute it to the construction of the replacement converter. I believe the converter is less restrictive so perhaps I'm getting slight performance increase.

...or the old converter was shot because it was clogged and the new one is breathing better, like it should.
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1998 S70 T5 Emarald Green Metallic (125K), 2004 V70 2.5T Ruby Red (45K), Previous Owner of Black '94 850 Turbo Wagon (Sold at 140K and miss her). My cars have been running so well lately they've got me worried.

When I took our S70 GLT SE to a local muffler shop to ensure all exhaust connections were tight, (which they were), the manager told me that the catalytic converter and the adjoining pipe were much too hot.

No codes are showing, car is running fine and gas mileage for this 2.4L Turbo engine is approximately 20.3 mpg.

Is this nothing to worry about or ???????

LP