whoa, hold on here. i need to get a bigger brain to weigh in on this, but i'll take a shot at it anyway. there are TWO oxygen sensors on our cars (at least there are on my 97, i'm not sure about a 93). the first one is on the rear exhaust manifold in the back of the engine compartment and is the more important of the two. it reads O2 levels in the exhaust as it comes directly out of the cylinders and is partially responsible for letting your computer know how to mix your air/fuel ratio properly. this sensor can have a big effect on how well your car runs in general, which is often reflected in fuel mileage. the other oxy sensor is located in your exhaust pipe immediately after your catalytic converter. it monitors whether or not the converter is working properly and removing the noxious gasses it'* supposed to remove, and as far as we know it doesn't control anything about how your car runs. the sensor you have may be the "post cat" sensor, the one that comes after the converter. i'm not sure how much these cost, but $16 doesn't sound right for an NGK exhaust manifold O2. i'll try to get someone else in here to verify what i've said, but if you go back to the parts store make sure to specify you need the O2 that comes BEFORE the cat converter, the one on the exhaust manifold. sorry if i'm way off base here.
1997 SE w/SLE package
"White curse? I think it'* more like.... WHITE FURY!" - MyLittleBlackBird