I've got 90,000 miles on my Outack, and I'm assuming it's time (or past time) to replace the O2 sensor(s). My mileage isn't what it used to be, and I'm thinking the sensors aren't functioning.

 

Anyway, could somebody tell me where the O2 sensors are on the 2.5 engine? I think I went hunting for them last year and found one of them, but not both.

 

Are they difficult to reach and replace? Thanks.

One will be just before the front catalytic converter and the second one will be in the mid pipe after the second catalytic converter.

Sorry if I hijack,

 

I just cleaned mine with BG 402 so I will let you all know what the results are.

 

However, why is it that there is no code generated when the Sensor is not plugged in? How am I even supposed to know that the sensor is functioning properly?