87 Corolla w/ bad gas mileage

[musette]

I realize my car is old and it doesn't help that it had been sitting for about a year, but the gas mileage is terrible. I used to go far with my 86 Nova that I know use for parts. Any suggestions that won't cost a fortune. I am not car savvy, but I know someone who is.
Thanks to any who suggest.

[Tofuball]

I say, give the car a tune up, and while you've got the plugs out, get your friend to check the compression (bad compression hurts fuel economy a lot).

Make sure your alignment is good and your tires are inflated correctly

If you havent replaced the O2 sensor in 80K miles, or dont know when it was last replaced, go ahead and replace it.

Also, you might want to change your driving style

Those are a few things I thought of off the top of my head.

[musette]

Thanks for the suggestions. I think the car had a tune-up right before I bought it, but I'll check again.

[CodyjCA]

how much is another o2 sensor?

[neonwater]

I had an 86 Corolla LE. I used to increase the spark plug gap, had a 2.25 cat-back exhaust installed with a borla muffler, had the catalytic converter replaced at 80,000 and got 34-37 MPG mixed city/freeway driving. I didn't drive it too hard considering it only had 75 hp. If it has a lot of miles on it, check the catalytic conveter. When I changed mine, it made a lot of difference. I never found out if it was plugged or a bad part. Hope this helps.

[Tofuball]

A bad cat could definitely cause bad gas milage, just like a clogged air filter. Cats usually conk out at just over 80K on most cars, but on the same token, it is not uncommon for them to last signifigantly longer (especially on cars that have been running rich)

If the cat is the problem, I say dont get the stock one (expensive, restrictive) I reccomend just getting a good aftermarket highflow cat such as a Magnaflow (~$100 at jegs.com) and welding it in place. Or if you have no emissions in your state, just get a pipe welded in.