DWS964

OK, it's not a major overhaul nor rocket science, but I thought someone out there might benefit from my O2 sensor replacement experience. The pic below shows the old sensor and the tools I picked up to complete the job.
First, the O2 sensor crow foot wrench/socket. Fits nicely over the sensor and uses a 1/2" ratchet to turn. $9.95 at AutoZone.
Soaked the sensor fitting with PB Blaster - thought that would help.
Nope, wouldn't budge, much. Then turned a little, more PBBlaster, turn a bit more. My hopes were rising. Soaked it again, Went in for a glass of wine. Came back the next morning. Turned a bit more, etc. The sensor finally came out, but left its threads behind in the cat. Panic. Cursing. I was not going to try using my new $135 O2 sensor as a tap to clean out the threads.
I discovered that O2 sensor threads are the same as 18mm spark plugs. So, I bought a spark plug thread chaser (dual 14mm and 18mm) for $7.75 and cleaned up the threads nicely in the cat.
The new sensor threaded right in, no problem. The car runs quite nicely now - no big problems before (94K on original sensor), but it does seem to run and idle a bit smoother. We'll see if the fuel economy improves.

TR6

I noticed there are different options for O2 sensors for our cars with the Bosch OEM style being the most expensive. What is really the difference between these? Is the connector different?

Superunknown

Interesting. How fiddly was it to connect the other end up in the engine bay? Do you need orangutang arms to get in there? And out of interest, how much was the o2 sensor? They charge £90 here (about $180?)

964rh

Thinking about replacing (or actually outting an O2 sensor on my car), It's been decatted and has no sensor fitted.
Have you got a pic of the connection in the engine bay by any chance? I think mine has been jumpered as both the ecu and in the bay and can't see the connection.

Rob

DWS964

re: O2 sensor connection in the engine bay.

Not sure if I can get a picture in there - I reached in along side the blower and found the wire coming up through the shroud. The new sensor (Porsche OEM - Bosch) comes with a new grommet installed (see picture) where it passes through the engine tin. I pulled the grommet out from the bottom side, and reached in from the top side, found the wire and connector (which is clipped into a bracket). I pulled it apart with one hand (not enough room to get 2 hands in there). Installing the new one was fairly easy, but a little tricky doing it one-handed. The connectors have to be lined up in the right orientation, but slide together easily.

I bought my sensor from Sunset, for about $135. Pelican price was about $155. There are some other sensors out there (Nippondenso) that claim to have direct fit (I assume this means OEM style plug connector). And then there are the "universal" sensors with bare wire leads that show up in the application listings. They might work, they might not. Beware.

ilko

The Bosch sensor is the most expensive one. I got a $29 sensor off Ebay that requires to cut the wires from the old sensor. It works just fine and it was very easy to install.

Edit: It was actually less than $29, shipping included. Here's the auction: http://cgi.ebay.com/ebaymotors/ws/eB...m=300114927132

tgage

FYI, you can purchase a Hazet type socket for under $5 at Harbor Freight for doing the 02 sensor replacement...

They also have a 22mm at the store outlets that will fit over the front shock. The 22mm one is large enough to put the allen wrench in to hold the shaft of the shock, plus you could put another wrench on top just like a sparkplug wrench.

could not find the exact one on the website.... but this is close.
http://www.harborfreight.com/cpi/cta...emnumber=95045

ilko

A 22mm flare nut wrench did the trick for me.

DarrylH

There has been talk in the past that the Bosch OEM sensors are "plunge-proof" while others may be subject to water ingress. My mechanic said the difference in cost wouldn't seem like much if the car died in a heavy rain as a result of this. FWIW.

TR6

Thanks for the tip, I just ordered one of these today. For $24.80 shipped, I'm willing to roll the dice on it. And it looks like it should actually be easier to install than the OEM by cutting and splicing the wires (theoretically...).
I'd be interested to hear from people who've used these aftermarket sensors to see if something like this has actually happened. I will certainly report if it happens to me after I install the one I've ordered.

dfinnegan

I had car trouble in a heavy down pour when I first bought my car. xmas tree lights, stall at speed in the left lane on the way to jfk airport. Not fun! Fortunately it restarted after sitting in the death zone for a while. I also had to chase the old threads out of the cat when replacing the o2 sensor. I've had no running problems in heavy rain since. ymmv.

TR6

Was this an aftermarket O2 sensor that was in it when you experienced that?

ilko

Yep, that's how I did it, it worked just fine. The only thing is to be careful when connecting the wires. There are two white and one black. I wasn't sure if mixing the white wires would be a good idea, so I retraced them to the base of the sensor before cutting and connecting.

TR6

ilko, can you clarify how tracing the wires back to the base of the sensor will indicate which white wire connects to which? Maybe it will be obvious once I'm looking at it. -thx

ilko

It's easy to trace the wires. They come out like this from the top of the sensor:

-O-
O-O

The top one is black (well that depends on how you position it) and the two bottom ones are white. It's the same configuration on the new sensor. I just cut one of the white ones first and connected it to the new sensor and then the other. I don't even know if it matters if you mix up the white wires, but they're really easy to trace so why chance it. You'll be fine, it's a piece of cake job