I just bought a '94 convertible for my wife. It runs OK, but is giving me th "Camshaft Position Sensor" fault that everyone seems to have. Someone put on dual exhaust, and did a good job of it, but one side has a crack at the top of the converter. I think that they're stopped up, judging from the lack of power and poor gas mileage. How should I go about putiing this thing into good working order again?