97 Highline horrible mileage

I'm only getting like 9 or less mpg..
Only additional things on car to my knowledge is performance headers and aftermarket dual exhaust..

I need serious help >_>

When is the last time you had a tuneup? Spark plugs, spark plug wires, fuel filter, air filter, PCV valve and so on. Might want to start there.

one thing that really, REALLY put a damper on my mileage was my brakes. it seemed that they all sort of went at about the same time. one of my rear drums were stuck a little on. just enough that i didnt hear anything, I only noticed because the smoke from the brake fluid. it couldnt hurt just to check it out. like i said, i didnt notice till i saw the smoke.

I had some non-stock size tires on my neon and was getting poor mileage. I went back to the stock size tires and my gas mileage improved quite a bit more than when I had the wider tires. Also, I keep the tires inflated to 35lbs and check them almost daily with a good tire gauge.

When is the last time you had a tuneup? Spark plugs, spark plug wires, fuel filter, air filter, PCV valve and so on. Might want to start there.

Fuel filters aren't servicable on neons, can't find.

It's in the tank. Gotta drop it.

IIRC the pressure regulator is a combo filter/pressure regulator.
http://info.rockauto.com/getimage/getimage.php?imagekey=1319380&imageurl=http%3A//info.rockauto.com/SMP/PR326_FULL.jpg

I had a bad upstream O2 sensor do that i was getting about 12mpg...