Could someone confirm what diameter spanner the O2 sensor takes?
22mm seems to be the most common size, but mine appears to be smaller - more like 20 or 21mm? and is pretty corroded.

I don't have those size spanners so I'm going to be have to buy them or a removal tool to get enough force on it.

Alternatively, what's the price on a Porsche replacement?

Is it a fairly generic part? i.e. like the 3-wire one here ---> http://www.cats-direct-shop.co.uk/lambda-sensors.php

if so , I'll just buy another and keep the old one in the cat.

thanks
Garry

 

I just changed mine out yesterday, I used a 7/8 wrench, came off very easy, I do not any rust on the car..you can get the part from just about any porsche on-line parts dealer, mine was Bosch 13084 cost $103 from AutohausAZ, I think I could have gotten it a little cheaper from Sunset Imports..
craig

 

Mine was a sod to do, So I smashed the bejesus out of it, then used a 7/8 IIRC socket to remove it.
£103 from OPC in Colchester, rather than the OEM ones that I had heard can sometimes be a little temperamental.
Kevin

 

With the location of the O2 sensor directly behind the rear wheel you're basically required to you use a plunge-proof O2 sensor or you will have running issues driving in the rain or even just through large puddles. So that means you can't use a generic O2 sensor, you must use a Bosch OEM or Porsche OE.

 

Thanks for the advice.
I have ordered the exact Bosch OE part from here --> http://www.lambdasensor.com/main/porsche.htm @ 20% off opc price.

So far i've spent double the cost of the cat bypass pipe in fittings alone :-(

I thought someone posted 30mins to fit the cat bypass....... I wish..

Garry

 

Ha!

It took me several hours over the course of a few days to get the bloody cat. off - I resorted to a reciprocating saw to cut the cat. off at the front square mount as the bolts were rusted solid.

Marc

 

My cat bypass came off easily. The impact wrench broke all four bolts in about 1 minute.

 

Rust? What is that? I've heard of it before, but have never actually seen any here in Texas...

ps. My cat came off with ease.

 

I think that is the secret of the 15,000 mile check up. Its purpose is to free underbody bolts before they seize, and valve adjustments and oil changes are just for show .

 

Check your rear axle crossover tubes, Porsche conveniently forgot to paint inside of them (they're still body-in-white) so if you are running around without an undertray and they ever get wet expect some minor surface rust.

 

22mm is definitely not the size of my (original?) sensor...spent three hours persuading it to break lose to no avail. Soaking it overnight in WD40 and will try again tomorrow. Why is it that despite having hundreds of spanners/sockets you never have the one that might fit!!

 

Three days later!!! The sensor is well and truly rusted into the cat. I've now removed the cat and will attack the problem again. Just for the record I have tried heat, mole grips, removed the top of the sensor and hammered a smaller socket over the base and three days of soaking the thread in WD40 (which contains no silicon - which kills sensors) - nothing seems to work and because the sensor has a softer metal ....!!!

 

I used a giant cressant wrench after soaking for about a day with PB Blaster and it came right out. The adjustable cressant wrench was large enough to allow good leverage.

 

At last its out!!! Found the reason too why I had such a job removing it - someone had cross threaded the last one. As my cars service history shows it has only been done by Porsche dealers and Porsche specialists it does make you wonder why you pay so much for 'skilled labour'.

 

You may want to buy a thread chaser to clean up the cross threaded opening.