My exhaust system sounded very loud like a muffler had gone out. I took it to Deerfield Tire $ Auto for a diagnosis. They told me the flex pipe was the source of the problem. Their estimate: 4 gaskets, 2 direct fit catalytic converters with flex pipe, 5.4 hours of labor for a total of $1929.53. The car had 42K miles. Decided I needed another diagnosis so I took it to Marc's. Their diagnosis was a broken bolt, that opened up the leak in the system at the exhaust manifold. Two gaskets later, it was fixed at a cost of $240.40 most of which was labor ($212), Thanks Marc.... Great job.