In this case, I'd think the course of action is to figure out what is making you rich, not to just adjust it. It sounds like you're WAY off, not just a little off which likely means there is some other problem.
I'd look for a boost leak. A shop will be able to pressurize your intake and look for leaks. Without an adapter and an air compressor this can be difficult to do for a DIYer. Smoke machine may help, but for a boost leak, it may not show without pressure.
To start, go over all the connections in the intake tract looking for small holes and loose clamps. You can try squirting something combustible (carb cleaner) around the joints trying to find a leak, but like I said, a boost leak may not show without pressure.
Do you have a Tactrix so you can look at long term fueling trims with Learning View? This will tell more of a story.