Running rich?

[immortal_suby]

I have had this problem for as long as I have owned my svx. (28k) When I open the sunroof I will have a gasoline smell coming into the car. It does not smell like unburnt fuel you smell at a gas station, more like a car that is running rich. I don't smell anything with the windows and sunroof closed. I also don't smell it much if I have the windows and sunroof open due to the increased airflow. I have put in new O2 sensors, reset the ECU a few times, the air filter is a clean K&N, all the vacuum hoses are connected and not visibly worn, the charcoal canister is connected properly (but probably the original) the intake is tightened down correctly, there are no error codes in the ECU.
It is most noticeable when I am at full throttle, if I drive like an old lady I hardly smell it at all. There is black soot in the tailpipe. When I put in new plugs about 10k ago, the old plugs looked great.

I have recorded the gas mileage for as long as I have owned the car and it ranges from a high of 26 on a long highway trip down to 18-19 that I am getting now around town on this crappy oxygenated winter gas. I normally get around 21-22 around town in the summer. I always burn 93 octane or better if I can find it.

Is my next step to replace the charcoal canister? Is this something I just have to live with? Does the svx just dump tons of fuel in to prevent detonation at wide open throttle or is my car screwed?