I recently developed what sounds like a hole in the exhaust system. When I crawled under to check what was leaking it appears the leak is on the "down pipe" where the (4) header-like pipes converge and go into the rest of the exhaust. IT seems strange to me that exhaust would be coming from that area and I'm concerned catalytic converter may be clogged and forcing the exhaust back out through the header pipe. Is this a possibility? Is this a typical Volvo problem? Mine has 233K miles and I don't know if that catalytic converter has ever been replaced. Any help would be appreciated. Thanks! TPW