I'm looking to replace the O2 sensors in my '99 non-turbo S70, this video shows steps on a 850 Turbo - question, how does the process differ on my car?


Thanks!


https://www.youtube.com/watch?v=-3Ve...ature=youtu.be

 

I've done them on my 850T and didn't quite use the same process in the vid so I'd say you should go under the car and take a look and see (keep in mind the vid shows a car on a lift, not on jack stands - big difference in terms of access). But first, as there are two O2 sensors - why do you think you need to replace one or both? Quite often vacuum leaks can throw codes for the sensors so check that first then look at how to test a sensor to see if one has failed before you spend $100 x 2 plus a few hours under the car...

 

Thanks - a P0301, Sensor Bank 1 triggered the CE light; not sure but if the need for one sensor is confirmed, heck why not replace both? I'm the original owner, 125K miles - any suggestions?

 

On my 850T, I was able to access the front o2 sensor fairly easily with the car raised about a foot on jack stands. I snipped the wire so I could use a deep socket and a breaker bar (plenty of PB Blaster helps). I used a crows foot to tighten. On mine, it was the front sensor that went at about 120K miles, the rear got swapped when I had to replace the front section of the exhaust /Cat (cracked at the front flair) at about 180K - since the cat was out of the car, I replaced both. The first time around I used a generic Bosch with the wire splice kit, which worked fine... Prior to that replaced the sensor on an Audi Quattro which required me to remove the cat from the car and drill out the sensor as it was so stuck in there... that's the risk of snipping the wire - there's no going back...

 

The front sensor (upstream) is used by the fuel system to calculate the amount of fuel being injected. It's very important it's working and working well. The second or downstream O2 only monitors if the cat is functioning properly and isn't as important.

I'd only replace the front O2 instead of both as that's the one you'll get the best gain in performance and there's nothing to gain doing the second.

You have no location in your profile but if you're in the U.S. you can get specific O2 wrenches or sockets on loan from Autozone, Oreilly ....
They can be quite helpful. Remember to apply anti-seize to the threads in case you still own it if it fails again.

You can get a little bag of it at most auto parts stores for a 1.50

 

Use Bosch sensors. Don't cheap out and use off brand types. The Bosch's will work, others may not.

 

Thanks guys! I decided to replace only the upstream sensor using an OEM replacement from FPC Groton, not necessarily cheap at $280 but I wanted to make sure there were no compatibility issues. My local, trusted and honest independent mechanic charged $40 to install. After a week and another couple of hundred miles the CEL remains quiet!

 

Life is good