Oxygen sensors

[krismorgan]

Hi all,i have to change the cat exhaust setion on my 960est(95 on log book but always says 96 when i put reg in anywhere) due to it cracking up the pipes near the cat.
Question is do i need 3 wire sensors or 4 wire,i know there are 2 sensors.
cheers.

[TonyS9]

Sorry I'm confused, why don't you just use the old downpipe or at least the O2 sensor.

Personally I would just cut the down pipe off near the cat and replace with a slieved joint and aftermarket cat, if the clamp is heavily rusted.

[krismorgan]

Both pipes have cracked where they join the cat,and if they are seized in there i will need new ones anyway

[Laird Scooby]

I'm also confused - if you know the pipes/welds are cracked, it's fair to assume you've seen them - why not look at the existing Lambda sensor while you're there and count the number of wires on it?

It's a good move renewing the Lambda sensor as they are electrically fragile and don't take the mechanical shock of being removed that well - as such used Lambda sensors usually fail in short order but in any case, they only have a service life of 10 years/100k miles so it's a wise choice to renew anyway, especially as a failing sensor will allow too much fuel (rich running) which will poison your new cat very quickly.

[baggy798]

They both look like 4 wires to me.

https://www.fcpeuro.com/products/vol...-s90-v90-15098

https://www.fcpeuro.com/products/vol...-s90-v90-15099

If you're having a garage replace it then ask for the cat back, the 960 original ones are worth some money.

[Forrest]

The one I bought last year to replace the post-cat sensor on my 1997 V90 is a Bosch LS5099 which appears to be four wires. I haven't actually got around to fitting it yet, so I may yet be wrong.

[krismorgan]

Originally Posted by Laird Scooby

I'm also confused - if you know the pipes/welds are cracked, it's fair to assume you've seen them - why not look at the existing Lambda sensor while you're there and count the number of wires on it?

It's a good move renewing the Lambda sensor as they are electrically fragile and don't take the mechanical shock of being removed that well - as such used Lambda sensors usually fail in short order but in any case, they only have a service life of 10 years/100k miles so it's a wise choice to renew anyway, especially as a failing sensor will allow too much fuel (rich running) which will poison your new cat very quickly.

I looked underneath when it started getting louder and saw the cracks/felt the blowing,have not took it off yet to see if the sensors will even come out or where the wires go.