The Check Engine light in my car came on. When I had it checked at AutoZone, the printout stated that it could be the catalytic converter or the O2 sensor needed replacing. When I try to crank it, it sounds like something is clogged. The other day, the car wouldn't start and I had to get a jumpstart to get it started.
From what you are describing it is possible the catalytic converters might need to be replaced. Before replacing them a back-pressure test should be preformed to verify that they are in fact faulty. After replacement, a verification that your engine is in good working order is also important because a misfire will dump raw fuel into the exhaust and quickly ruin your new catalytic converter. I recommend having a certified technician diagnose the Check Engine Light to make sure every gets fixed in working order.