1995 Ford Mustang excess fuel in tailpipe

I went to get my car smogged and it wouldnt pass, I was in the 500's when you should be under 100. I have excess fuel comming out of the tailpipe. It bogs and shakes, and when it idles it only idles at 500 rpm's. I check the spark plugs and spark plug wires and that doesnt seem to be the problem, can someone please give me any ideas or anything that would help me to fix it as soon as possible?