1999 S80 T6 Replacing oxygen sensors / best practices?

Post by **Riba** » 13 Mar 2014, 01:57

I have two oxygen sensors that need a replacement, but before embarking on this operation I wanted to hear back from the community.
What I am particularly interested in are the following questions:
- I have seen on several places advice to change all 4 sensors at the same time. Since this is not a small investment, is this something I should do or just change the bad ones?
- There are also reports that "third party" sensors like Bosch or Denso are not "good enough" and produce errors.

Any opinions or first hand experiences with this? Also, what is the recommended place to get these?

Thanks!

majorcode · Post by **majorcode** » 13 Mar 2014, 02:37

Riba, How sure are you that your oxygen sensors are gone. Probably by diagnostic tool?

If you have less than 200,000 KM then
1. Check any air leaks around they might bring the O2 errors.
2. Just two weeks ago I got error of Stop safely, Urgent Engine System Service with Lambada sign (Which was O2 Error actually), I restarted the computer but popped again just after 20 KM Drive. So I remembered that it was almost first time ever I did not check the petrol guy how he tighten the gas cap. So very next day I tighten myself/restart computer...that's it. Never see the error again.

Now the tricky part, I suggest buy OEM parts from reliable vendor, you wont regret it. Because they offer return warranty.

Post by **Riba** » 13 Mar 2014, 04:19

Well, when I got the car there was some wiring and connector hanging loose underneath the car. I told myself I will check it but in the mean time the Kuwaiti roads have ripped off the connector so I am pretty sure I have wires hanging from one of the sensors. It probably wasn't plugged in the whole time but I suspect it didn't just unplug itself by accident, and now it is too late to plug it back in. This is one of the sensors the diagnostics is reporting problem for (duh!). I guess I can go to junkyard and rip the connector and wiring and try to plug it back in, but I don't think I am lucky enough that it will work just like that. Might be worth a shot though. This is one of the back sensors.
There is error reported for another sensor, front one in this case and for a different bank.

That is all I know right now, but I am thinking I should have new ones ready if I am going to take down the exhaust...or maybe I should inspect it first. So many questions.

Another problem is that I can't locate all the O2 sensor connectors, and I still don't have a copy of VADIS, and can't find it online. I guess I should go for ebay but it will take too long to ship it here (if it ever makes it).