1998 Volvo V70 T5 O2 Wire Harness connectors

ryoung3300 · Post by **ryoung3300** » 21 Jan 2018, 10:07

I have a 1998 Volvo V70 T5 that my kid's drive around and we had to do some repairs, Turbo, exhaust, and O2 sensors being the main culprits via codes and visual inspection (exhaust). After rebuilding the turbo we are now ready to start putting the pieces back together. Well, when we disconnected everything I did not realize that we had disconnected the O2 sensors from their respective wire harness connectors. I have been researching for a few days and have not found anywhere that tells me definitively which wire harness connector goes to the Front O2 Sensor and which one goes to the Rear. One website had one connector number listed as the Rear, and another website had the other connector number as the Rear.

The connector numbers are: 3545972 and 3545970
I know that the sensor are specific to the front and to the rear and switching them can lead to all kinds of fun and my fun meter is pegged!

Thanks and look forward to your responses!

Post by **misha** » 21 Jan 2018, 15:16

Black is for front and grey for rear o2.

Post by **abscate** » 21 Jan 2018, 15:24

You will also pop a “ switched OXS” code if you swap them and have a code reader.

No big deal if you get them swapped in the driveway.

Post by **wizechatmgr** » 22 Jan 2018, 00:58

ryoung3300 wrote: 21 Jan 2018, 10:07 After rebuilding the turbo we are now ready to start putting the pieces back together.

How did that turbo rebuild go? Just bearings and seals or did you encounter additional trouble? I have one I am going to be doing this spring.

ryoung3300 · Post by **ryoung3300** » 22 Jan 2018, 15:47

Thanks for the replies! I will look again, but both connectors looked black to me. Roger the switched OXS” code! What is the saying, "If at first you don't succeed, try, try, again!".

As far as the Turbo rebuild I used the TD04HL Turbo Rebuild kit (Flat Back) from ARD. It worked like a champ and it helped that they had a you tube video. I just replaced the bearings and seals and did not upgrade it to a Super Back.
Thanks again!