Chevy equinox has problem with exhaust and losing power

If the exhaust system is crushed and the exhaust can't flow freely through the exhaust system the engine can't "breathe" correctly and you will have a loss of power. Also if you have an exhaust leak fresh air is probably being pulled into the exhaust system, past the upstream oxygen sensor. When this happens the computer falsely sees an overly lean air to fuel mixture and tries to compensate by making the engine run excessively rich. This will cause a lack of power, misfiring, and possibly black smoke out the tailpipe. If the catalytic converter is plugged you will have a loss of power as well because the exhaust can't flow freely through the exhaust system, just like a crushed exhaust system. Hope that helps! Jim

Catalytic Converter meltdown.