Oxygen sensor replace

volvolover · Post by **volvolover** » 05 Feb 2005, 20:54

I found a posting for changing spark plugs on a 850 and it was excellent. Looking for a similiar detailed posting on replacing a oxygen sensor.

The reason I'm replacing it b'cos my 86 Vovlo (76k miles) is giving only 14mpg. I bought the car just 6 months back and I wa shoping it would give at least 18-20. Got the timing belt changed by the dealer. but I'm thinking of changing the spark plug and the oxygen sensor myself.

Also, any idea on whether I should be replacing the After Catalyst or Before Catalyst sensor ? How do I find out.

Thanks everyone for helping me.

White850Turbo · Post by **White850Turbo** » 06 Feb 2005, 11:02

The o2 sensor that determines your A/F ratio and therefore your gas mileage, is the one before the catalytic converter. I'm not totally sure what model you're talking about doing this on, but I'll assume it's an 850. All you need is a jack, some jack stands, a 22 mm wrench, and a long straight-slot screwdriver. Jack the car up and get it on the jack stands. Follow the sensor from the exhaust to where it plugs into the electrical connection. This is a little tricky the first time, but it works believe me. I've done it TONS of times. The sensor plugs into this red socket looking thing. What you want to do is take the long screwdriver and wedge it between the o2 sensor connector and the red socket. There's a tiny sliver of space to fit the screwdriver in. Wedge them apart and pull the sensor out. Then just take the o2 sensor out of the exhaust pipe w/ the 22 mm wrench. Installation is reverse of removal. Good luck.

volvolover · Post by **volvolover** » 06 Feb 2005, 14:21

thanks for your posting. Mine is a 850 1996 Volvo. Sounds difficult since I dont' work on cars. I'll look around for a car manual to see if there are any pictures explaining this.

I see that you live in Plano, TX. I also live there. Thanks again.

Post by **matthew1** » 06 Feb 2005, 15:14

Check your codes to see if it's an O2 sensor at all. The code will probably tell you which one it is.

If it is O2 sensors, this might help:
https://www.matthewsvolvosite.com/chat/p ... php?t=1581

volvolover · Post by **volvolover** » 06 Feb 2005, 22:59

Thanks Mathew. How do I read the codes from and how do I read the codes ?

UncleBoost · Post by **UncleBoost** » 09 Feb 2005, 09:13

hmmmm a Volvolover who doesn't work on cars.
$$$$$$$

Man, you must be very Rich or just learning.
After owning 3 Volvos, I could be a Volvo Mechanic as a 2nd occupation.
We'll check back in a few months and see if you still have the same Name.

[][] { \ } [][]

U-Boost

Post by **dosbricks** » 09 Feb 2005, 12:42

UncleB,
I think volvolover just got his car, but I still have a little attraction for my wagon.

UncleBoost · Post by **UncleBoost** » 09 Feb 2005, 13:10

I know Dosbricks......
I love my wagon when its running.
I get so frustrated though when it puts me down at the most
inconvenient times. Like going to work!!! ha hahaaa.
I have since come to realize you Love your volvo when its running and hate it when you can't find the problem, and youre at the mercy of "Land Shark" mechanics when youre 100 miles from home at work...(My scenario) and its your 2nd car but most funnest to drive! (Grammer check uh oh!)

I was being sarcastic at Volvolover cause i started out like he did.
Then came the fuel Pumps and the Oil seals and the timing Belts and the many times on the Hook of a tow truck...and yet I still have this car.
And I would hate to compare it to the British car I used to own back in college days but it was getting darn close!

My wife made me write 100 times on the blackboard "I Love My Volvo"
...but i love her more!
The adventure continues........