Bobbydigital

My eEngine management light came on and I had a diagnostic check ran to find the fault. Code came back with the Front 02 sensor. Now I know there are two front sensors that are easily accessible, so I simply changed them alternately to see if this cured the problem. It hasnt! The EM light is still on. SO i have two questions.
Firstly, are there more than two sensors that would count as "front" as i believe there are 4. Secondly, does the system need to be reset for the light to go off?

05545i

The code needs to be cleared after replacement.

pauliehcfr

There should be 2 front O2 sensors and 2 rear O2 sensors. They are different. The code has to be cleared after replacing them, however, if you continue to drive, and the engine computer no longer sees the fault, it will automatically erase the fault and turn off the light. It takes a while though....couple of driving cycles

Bobbydigital

Guys thanks for the info. I will also check if the two "top" sensors are different as this may also be why it has not cleared the fault.