Is there any way to tell if my o2 sensor is bad? [Archive] - Toyota MR2 Message Board

milage, miles, sensor, pretty, gained, shape, appreciated, ignition, rotor, coil, 1-2mpg, brand, bought, averaged, 34mpg, 8,000, distributor, replaced, horrid, drive, perspective, recently, good, averaging, city, 19mpg, replacing, wanted, find, highway, rarely, plugs, wires, beat, 5sfe, fill, 21mpg, tank, higher, 3,000

I just wanted to know if theres a way to find out of my o2 sensor is bad before I go about replacing it. I havent been getting very good milage recently. Ive been averaging maybe 19mpg city and maybe 23 highway (usually it comes out to about 21mpg when i fill up the tank). I know it should be higher than this on my 5SFE. I dont beat on it to much. I rarely ever rev it over 4k. The plugs and wires have less than 3,000 miles on them and my distributor cap, rotor and ignition coil are all