O2 Sensors on '95 GM

[miamibob]

Hi!

I have an '95 GM Dual Exhaust that I received with 185K on it. Since I did not buy it new it is difficult to know what parts have been changed and when. I have noticed the gas mileage is not great (according to the Digital readout approx 15-17 city). Did plugs,wires, MAF cleanout and the brakes/emergency not binding. Also cleaned EGR ports and replaced TP sensor. There is no CEL and no codes but I have heard of "lazy" O2 sensors playing havoc with gas mileage. What if any are the cost/benefit advantages, gas mileage wise, of just replacing all four sensors? Rock Auto has them for approx $43 each, without shipping.

Since I am suffering from a serious illness I am not thrilled about crawling under the car to replace them if there will not be a decent benefit. Don't want to pay the labor for something I can do so hence this question. Thoughts please????? Thanks....MB

[way2old]

Hello MB. Glad to see ya. Check this link. Your vehicle is in range. You need to do the mileage the old fashioned way. Send me a note so I know what is happening.

http://www.fueleconomy.gov/feg/bymake/Mercury2005.shtml