Engine Mechanical problem
1999 Toyota Corolla 4 cyl Front Wheel Drive Automatic 200 miles

I have 1999 TOYOTA COROLLA 2 month ago I got P 0466 fail code then I change Charcoal Canister Then reset ECM CHECK ENGINE light became off.But now i cannot pass smog check because too hi CO.. I already change spark plugs injectors-nothing changes.. Car runs good ,doesn,t eat gas, CHECK ENGINE off-no one can tell me exactly what else am i supposed to change?????