Romadoc

My '98 ES300 (55,700 miles) check light came on yesterday. According to my Lexus dealer, it is the Oxygen sensor ($312) and this is a common happening. I told him that I have to do a 1000 mile trip tomorrow and he said it was safe to drive. I am exempt from my state's emission requirement due to a combination of car age, low annual driving mileage and my own senior citizen age. Should I or is it actually necessary to replace the sensor.

Lexmex

Knowing which number they pulled out of the computer would be helpful. There is an oxygen sensor after the main catalytic converter and if you are exempt from the test, that is no big deal at all. However, the other 'oxygen' sensors known as air/fuel sensors (there's 2 of them) closer to the engine, if not replaced over time, can lead to a loss in mpg. Right now, it is running in a default mode where the vehicle's computer send a code to keep the air/fuel ratio at a certain predetermined ratio.

llcoolpass

like he said i but its very important to change the before the cat, also called upstream, oxygen senors when the computer flags them since they have to be really bad for it to flag them. takes not long to change 02 sensor, surprised you didn't just do it before your trip but that's not here nor there. yes before hte trip do it, cheap and quick too, very important for engine operation

ASG14

iTrader: (1)

Does the $312 INCLUDE the labr to replace it? The sensor itself should be $175 (I think). If they didn;t give you the code, you can go to AutoZone (free), and they will read the CEL code for you, and let you know.

Your fine to drive with it though. But replace it as soon as you get a chance. right now it's likely making you get worse mpg. It's unusual for the sensor to go bad at this mileage, but the car is also older. So it doesn't surprise me really.