97 Tercel lacking power and gas milage.any suggestions

[greenbla]

To give a little background, this car was completely tuned ~6000 miles ago. The car now has 67,000 on the clock , it's barely getting 30 miles to the gallon on the highway and it drops speed considerably on hills, even when your doing 80 at the bottom. It's not using any oil and all cylinders are right around 180psi. other than power and gas consumption, it seems to run fine. Any ideas of what could cause this?:(

[Monster-Mat]

is it an auto....

are the brakes binding...

[greenbla]

the car is a 5 spd, the brakes don't seem to be binding, at least there is not smell and I put alot of miles on and they haven't worn through the pads. I'm going to replace the cat tomarrow, I'm not totally convince that that is it, but I got a cheap universal one, so it's worth a shot.

[greenbla]

Well, I changed the cat. The old one didn't seem too clogged, but the new one is a high flow so I put it in anyway. One the test drive after installing the cat, it finally trough a check engine light and a code for secondary oxygen sensor failure, I think this was probably the culprit all along.