o2 sensor??? 350z!

[Roninmedic82]

How can I tell if my o2 sensor is bad?

Coming back from Texas the other day I stopped to fuel up and my gas milage dropped from 28.5 on cruise@75mph to 22.4, 23.4 on cruise at 75 to 80mph. The filter will be cleaned and plugs changed, but I'm afraid I got some bad fuel that I've heard stories about.I've heard that if the sensor goes bad , fuel milage drops significantly.

[xjmxstac]

http://mr2.com/TEXT/O2_Sensor.htmlI hope it helps!

[Jacko3]

If O2 sensor goes bad, CEL will come on, and gas mileage will also drop. Did CEL light come one???? Was ther any other symptoms associated with the drop in mpg????? Are you sure the gas you pumped into the car was premium gas????

[Roninmedic82]

ya its always premium, and no lights came on. regardless new sparkplugs are going in and my CAI filter needs to me clean, but the symptoms were acute and havent gotten better.