Need Advice About 02 Sensor

[creslevi]

I have a 94 LeSabre 3.8 V6 with 217,000 miles
everything but the spark plug wires is original, it runs fine but lately my gas mileage has dropped off quite a bit, I don't have a clue how the 02 sensor operates except that it senses the load and adjusts the mixture Rich or Lean, If I just put a new 02 sensor on how likely is it to increase my mileage ?, From reading a lot of the previous posts here I know a person can throw a lot of money at it and not gain a thing, So it's an easy matter to post this question and hope for some responses that have done this, Thanks a bunch for your help.
Rick

[sierrap615]

the key to fixing a car cheaply is proper dianostics, unforuncally, the tools for a good dianostic cause alot of money, so if you want to try to save some money-

1. check airfilter
2. check tire pressure
3. need a tune up? including plugs, wires, and fuel filter
4. body damage?
5. engine tempature normal? it doesn't take to long to warm up does it?
6. have a shop do a fuel injectior cleaning, not just the stuff you put in your tank, the type where they tap into the fuel rail.
7. for the O2 sensor - remove it (in your case i beleave there are 2) and visually inspect it, if it is covered in carbon or anything resricting airflow inside the cage, it needs replaced, it can not be cleaned. i normally consider any O2 sensor with 150k - 200k+ miles trash

also does you state do emission testing?

[creslevi]

Thanks for the reply, I will take a look at it, I have never seen one before this car, and it's been trouble free for almost 10 years, I will post what I find out.
Rick