Hi, Folks,

The dealership in town changed out both catalytic converters on my 2002 E320 last week under warranty, (no questions asked, 79,600 miles). Since that time, my in-town fuel mileage has dropped from about 20 mpg to 10 - 11 mpg. The exhaust sounds louder under part-throttle operation. The car seems to have a harder time starting, though it runs fine after a few seconds.

I've contacted the service adviser at the dealership, but haven't heard back from him. Prior to speaking with him, I was wondering if anyone has an idea regarding the cause of the new symptoms I'm describing.

Thanks, in advance, for your help.

Steve