1999 V70 xc 2.4l oxygen sensor locations?

kovi · Post by **kovi** » 12 May 2014, 12:16

HI. can someone let me know WHERE the second O2 sensor is please? I found the first one in the inlet of the cat converter but, I cannot find the other one to save my life and I still keep getting a p0030 code... help?!

Post by **erikv11** » 12 May 2014, 14:47

There is one before the cat, and one after the cat. For the rear one, you must you look from underneath the car. Helps tremendously to get it up on jackstands or ramps first.

kovi · Post by **kovi** » 12 May 2014, 15:20

I understand the second one is after the cat.... but, is it at the right at the exit of the cat? further down the exhaust pipe? near the resonator? between the res and the muffler?
I've had it up in the air and cannot see nor feel anything.... was there a model that only had one sensor?

Post by **erikv11** » 12 May 2014, 15:31

Check out these 850 pics, can you rule out this location?

https://www.matthewsvolvosite.com/forums ... =1&t=45547

Post by **Ozark Lee** » 12 May 2014, 15:40

As I recall the rear sensor is actually threaded into the catalytic converter itself, towards the back.

...Lee

Dirk1966 · Post by **Dirk1966** » 12 May 2014, 22:38

On my XC70 the second in the front of the cat itself.
See the picture number two on this page

https://www.matthewsvolvosite.com/forums ... p?p=105215

kovi · Post by **kovi** » 13 May 2014, 04:05

ok.... if the one at the front of the cat is the second one....then ...where is the first? lol

Post by **erikv11** » 13 May 2014, 07:09

More up front, like in (or almost in) the engine bay ... look at the downpipe with the hood open.

Post by **Atis** » 13 May 2014, 10:23

For example I do not have a second O2 sensor... There is no signs plugged hole or any indication for that, just an empty plug next to the front O2 plug (98 S70 GLT).

kovi · Post by **kovi** » 13 May 2014, 11:31

Thanks Atis and everyone else that's trying to help. for those curious, I am a machinery mechanic for a living but, have never worked on Volvos in my life. I'm working from ramps because I do not have a lift at home. I did replace the sensor at the front of the converter (as shown in the pics linked above) after getting a P0133 code. now, I get a P0030 code since that one was replaced. I am guessing that there is either a second sensor that I cannot find....or the one I replaced is bad. thoughts??? anyone???