Problem w/ MPG on my '81 Corolla....O2 Sensor bad?

[dandingo]

I'm brand new to this site and I just got this car a few months ago and have done the following things: Changed oil/oil filter, new waterpump, air filter, and fuel filter and the guy before me put new wheels/tires, batter, muffler, cat converter and struts. I'm only getting like 20 mpg in the city and I baby it. Could it be the Oxygen sensor? I don't wanna throw down $40 unless I'm sure that's what it is. How do I check to see if it's bad? What about the plugs or getting it aligned? It pulls to the left so that's probably not helping. I wanna get as much MPG out of this badboy as humanly possible. Any help would be appreciated. Thanks in advance!

[gdpeters]

My wife owns an 81 Corolla. We had it tuned up last year. The last time I check it was getting 22 mpg in the city.

By the way, would you be willing to send/post a picture of your Corolla and let me know how much you paid for it, its mileage and overall condition?

I plan to sell my wife's Corolla in a couple of months and I trying to compare it to what else is available.

Thanks.