Air filter smells like gas?

So no doubt I'm beating a dead horse and am bringing up an annoying question;
But I just replaced my air filter, took it for a spin or two and checked it a day later and it smells no better then the old one. Strong gas smell and it seems to be getting too much fuel, seeing as that my fuel mileage is horses*** and I just drive to work and back on the free way. Maybe 200 or so miles to a tank for a V6 seems kindof bad. I got better with my 350 vortec when I had it.
My o2 sensor is a 3 wire, which is also weird seeing as that it is a 93.
The only thing I can think of perhaps is maybe the exhaust is too small? I have 2 1/2inch coming off the y pipe and then into a 2 1/4 after the muffler. But that doesn't make any sense either.
And on top of all of this, It doesn't idle high when the block is cold. It idles all the same.
I replaced the coolant temp sensor too.
This thing is driving me nuts.

Are you getting any codes on the dash? A rich condition can be caused by many things, the CTS being one of them. Even though you replaced it, check it with an ohmmeter: http://67-72chevytrucks.com/vboard/showthread.php?t=425788

If it checks out, the O2 sensor may be reading incorrectly and causing the ECM to dump more fuel than necessary. I'd consider replacing it if it's never been replaced.

If all that checks out, search around for "tbi running rich" and go from there.

I'll have to do that cause now its running a little worse. harder to get up and go.
I'll change the O2 sensor and give that a shot. I just really like this truck and I dont want it to be a problem child.