Hello,
my neighbor has a non turbo 98 854 with 70kmiles on it. Always been a very reliable and well-performing car. Recently, it started sounded like it has a hole in the exhaust or a more throaty sound, like a rice-rocket motorcycle, especially at idle. No holes, same exhaust. Also the idle fluctuates a bit, it will drop down low as if it were going to cut off, then will jump back up to normal. It is strange enough that people look at her at stoplights to see what's up.

I checked under the hood, and all the vacuum hoses look OK. The only obvious problem I found was that the intake hose from the grill to the air box was broken, and not taped back very well. Could the under-hood air be causing this problem? I will replace that for her of course, but wonder if something else was damaged by the hose problem (O2 sensor?).

Thanks for the help