bad gas milage
 

i usually make around 13 mpg in my stock 90 GT w/ 114k in NYC. I now make only about 11. The car has fairly new plugs, wires, cap, rotor, fuel filter, air filter. Timing should be good. I was making good mpg after all these items were replaced but recently my mpg has gone done. Any ideas? I was thinking maybe O2 sensor?

Check for codes. Some say replace the o2s every 60K or so but I've had 3 5.0s with well over that many miles on their o2s and they get good mileage (could be better w/ new o2s I'm sure). They do become less sensitive over time.