# Downstream o2 sensor harness pigtail connection **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** electrical-wiring\ **Created:** [June 21, 2019, 6:11am UTC](https://community.cartalk.com/t/downstream-o2-sensor-harness-pigtail-connection/142686 "2019-06-21T06:11:25Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![Miguelgonzalezpaniagua\_153582](https://avatars.discourse-cdn.com/v4/letter/m/8baadc/32.png) [@Miguelgonzalezpaniagua\_153582](https://community.cartalk.com/u/Miguelgonzalezpaniagua_153582)\ **Post date:** [June 21, 2019, 6:11am UTC](https://community.cartalk.com/t/downstream-o2-sensor-harness-pigtail-connection/142686/1 "2019-06-21T06:11:25Z")
I have a 2003 passat 2.8 I have a car with a p0431 the guy said the pid for downstream sensor was fluctiating and that it should be steady so he reversed the harness conectors between bank 2 and 1 and the pid was fluctuating in bank 1 so he knows its not the catalitic converter we had already changed both downstream sensors so we know its not that the only thing he found was that a pin for the bank 2 downstream sensor harness was broken he went to the junk yard and cut a pigtail harness to add to the old broken one did he do something wrong connecting the splicing the harness we know its not the catalitic converter or downstream o2 sensors ---
**Author:** ![Mustangman](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/mustangman/32/44130_2.png) [@Mustangman](https://community.cartalk.com/u/Mustangman)\ **Post date:** [June 21, 2019, 1:48pm UTC](https://community.cartalk.com/t/downstream-o2-sensor-harness-pigtail-connection/142686/2 "2019-06-21T13:48:34Z")
Your mechanic did all the right things. Not sure why you are asking a question. Did the problem get fixed? If it did, drive on. If it didn’t, the damage at the pin is now fixed and your mechanic can move to the next problem.