looking in the haynes manual it seems there are two, an upstream sensor and a downstream sensor, to remove the upstream sensor, trace the wiring from the sensor located on the exhaust manifold to the connector and disconnect it. Unscrew the sensor from the manifold using a deep socket.

To remove the downstream sensor, raise the front of the car and support on axle stands. Trace the wiring up from the sensor, which is located behind the catalytic converter at the rear of the front subframe and disconnect it at the plug. Unscrew the sensor from the exhaust and remove it.

HTH

 

Thank you for your advise.

I am not so car technical and still locating it would be hard for me but I will follow your advise and hopefully i would be able to find it.

I hope someonce can post a picture where exactly is it.

Many thanks.

 

The sensors are located where Asterix says.

The Upstream O2 / Lambda sensor is located behind the engine and you are probably not going to be able to see it directly so you will have to feel round for it.

As access is limited you will need a special lambda sensor socket to remove the upstream sensor they are all pretty much a standard spanner size.

 

nice one SF

 

To take the photo of the Lambda sensor in place I had to put the camera round the side of the engine and take it blind!

I’m glad I did as I’d dropped my favorite ¼ “drive ratchet just before we had all this wretched snow and couldn't find or feel it anywhere. It’s on top of the exhaust to the top right of the photo.

 

Thank you SF. I will check and take your advise.

The reason why I need to replace the o2 oxygen is because my car is consuming so much petro, ithink its only about 25 mpg. I think this all started when I replaced the 4 coils but I am not 100% sure if this is related and just only a coincidence.

I searched this through this site and other forum and most of the information that I got points to o2 sensor. If you could advise on this that would be great otherwise I might open another post.

 

Yes faulty O2 sensor can cause excessive fuel consumption and poor running though if this where that case I expect the "SERV" light to be on and there would be an error code stored in the ECU.

A faulty engine temperature sensor can also lead to excessive fuel consumption if the ECU thinks the engine is still cold. This won’t necessarily generate a fault code if the sensor is still working

 

hi im looking for information , i have purchase a 4 wire universal lambda sensor but cant get the wire colours to match was wondering if you or anyone else knew which is which .i have an 05 plate scenic 1.4 16v , the wire colours on the original sensor are black grey purple white on the car they are green white purple grey, on new sensor the documentation says they are 2 white(h) black (S) grey (g)
thanx in advance for any help

 

I have tehE folowing troublecode:
P0032 H02S HEATER CONTROL CIRCUIT HIGH ON BANK 1, SENSOR 1

THIS IS THE OXYGEN SENSOR FROM THE EXAUST?