I just fixed all my problems with my motor, or so I thought. It was running really rich and it was missing. It threw a bunch of codes. Now it runs good but it blows out some black smoke if I jump on it and then let off. It doesnt back fire or miss or even smell rich if I just roll into it. Could it be left over raw fuel in the cat or someting from when I ran it when it was running really bad before? Its all carbon smoke, there is no oil being burnt. So what is going on?