Rear heated oxigen sensor for the volvo s40 2001

Oreste · Post by **Oreste** » 24 Oct 2009, 18:48

Hi I have a Volvo s40 2001 1.9 turbo and is giving me problems when starting the rpms are unstable and it turns off frequently specially with the a/c on... I thought it was a vacuum leak and I replace a hose that it was broken but it continues to do the same and the fuel consumption has increase quite a bit. I went to the mechanics and the scanner says that the rear heated oxygen sensor is missing (no working). My question is could this oxygen sensor be causing this entire malfunction?
Waiting for your reply
Many thanks… best regards

Post by **OEMVolvoParts** » 26 Oct 2009, 12:18

Whenever there is fuel related issues with the early s/v40 I always want to say its the fuel pressure regulator. They go bad all the time and cause issues like you describe (hard start). The idle issue could be due to the iac motor failing.

The extra fuel comsumption issue sounds strange, not sure what would be causing that.

Post by **uhlan** » 30 Oct 2009, 19:35

I have a 2000 S40. Did some muffler work last year. Looked for a rear oxygen sensor but didn't see one. Are you sure these earlier model S40's all have this rear oxyen sensor? If so, where is it located?

keithatcpt · Post by **keithatcpt** » 08 Nov 2009, 22:14

Here is a picture of the catalytic converter for a '00 S40 with the front (pre-cat) and rear (post cat) shown. The rear o2 sensor is highlighted. The front o2 sensor is on the top of the catalytic converter.

- Keith