Definitely the tune.

Might want to consider changing your fuel filter and your IAC and see if that helps any. With gas mileage that bad though you have GOT to be running incredibly rich.

yup, i guess thats what you get when you get a mail order tune for 93 lol.

im doing a complete replacement of a lot of things, air filter, fuel filter, spark plugs, engine oil, tranny oil, break fluid, coolant as well as installing L/T headers and catted h. then i will go to evolution performance to get it tuned