96 villager poor gas milage

wow, nobody has been here in quite a while! anyway, my villager was gettting good, not great milage in the warm weather but after the wicked winter we had here in upper mich, down to 25-30 below! it has gone down to maybe 10 mpg runs great, no miss, and replaced plugs and wires. any suggestions? removed the maf plug and it runs worse! maybe plugged cat convert? any help would b great!