SteveB

Listers,
What is the going rate for an OEM O2 sensor for an '86 951? I was quoted $180 from the dealer. Are these Bosch? Does anyone have an equivalent Porsche/Bosch part number? Any place to get them cheaper?

How can the existing one be tested to see if it needs replacement?

How difficult is it to replace...any tips?

Thanks all,
Steve '86 951

Skip

Not unreasonable for the stock unit to run $150-180. You can, and most do, replace with the Bosch universal 3-wire for just under $40. The only difference is the connector - you must splice the wires. You can also upgrade to a 4-wire with dedicated ground for ~$50 - provides some benefit over the standard 3-wire.

Easiest test is to unplug and note any changes in engine idle performance (should go rich - may smell change in exhaust fumes). Should be replaced every 60k miles regardless.

The r/r is quite easy - but may find you need the special (yet standard) O2 sensor specific socket. Many folks have luck with a stuby hand wrench - some do not. It's located on the header output, just as the pipes go horizontal - must lift car to get at.

Good Luck!

Jonathan Martini

autoatlanta.com :
Part Name Part Number New Refurb Used
OXYGEN SENSOR 951 606 135 00 $185.00 $145.00 $75.00 --

or maybe

OXYGEN SENSOR (USA, CDN) 944 606 133 00 $130.00 $75.00 $35.00 --
OXYGEN SENSOR (CALIF) 944 606 135 00 $230.00 $75.00 $35.00


Replacement and used are subject to availability, I'm sure. I don't know how good these guys are for mail order, but I've had nothing but good experiences in person.

Check Paragon. (Hi Skip!) Everyone here raves about their mail order service and prices.

Good luck.

luckett

The generic Bosch sensors #s are:

3-wire heated: 003913
Single wire universal: 11051

Available at any local auto parts store.


I do not recommend Automobile Atl. I had a bad experience with them on a simple repair job.

Skip,

Do you have an image of this O2 sensor socket?

luckett

[quote]Originally posted by Jonathan Martini:
<strong>Replacement and used are subject to availability, I'm sure. </strong><hr></blockquote>

Never install a used O2 sensor!

Steve Cooper

[quote] You can, and most do, replace with the Bosch universal 3-wire for just under $40. The only difference is the connector - you must splice the wires. You can also upgrade to a 4-wire with dedicated ground for ~$50 - provides some benefit over the standard 3-wire. <hr></blockquote>

Skip,

Have a wire splicing diagram handy?

Cheers,

Steve Cooper

Skip

[quote]Originally posted by chris luckett:
<strong>Skip,

Do you have an image of this O2 sensor socket?</strong><hr></blockquote>





3-wire = 2 white for heater (non-polarized), 1 black for sensor

Skip

luckett

[quote]Originally posted by Steve Cooper:
<strong>

Skip,

Have a wire splicing diagram handy?

Cheers,

Steve Cooper</strong><hr></blockquote>

White to white (2 wires, both the same), black to black.


Skip,

I thought you were refering to a socket tool for removal of the sensor.

zucker

OK I thought I would put in my two cents because I am a development engineer for Bosch Oxygen Sensors.
First of all let me check on that replacement universal 3 wire as it may not have the correct ceramic for your application.
Believe it or not there are different ceramics and more importantly different heater powers. The heaters in the sensors come in two different varieties of 12 and 18 watts. Lower power heaters will take more time to light off(time it takes for ceramic to heat up and become conductive). More than likely it's a 12 watt heater and the ceramic may be ok. If you wait until Monday and tell me the year, model of your Porchy I will know exactly what it requires and I will let you know if you can use the universal with no problems.
The protection tubes and ceramics play a big role in where the sensor switches its voltage when the mixture changes from rich to lean. Most of Porsche's sensors tend to be lean switching sensors and using the wrong universal(there is more than one universal)could effect catalyst life.
Also, it is important to use the unversal connector system. Do not use butt connectors when hooking these things up. The sensor must replenish the reference air inside in-order to create the oxygen gradients necessary for voltage generation. The sensor acts as a battery in a rich gas environment(long story). The reference air is replenished through the wire harness.
Anyway I could go on and on and bore you to death but let me know about your vehicle and I will see what I can find for you.
OK?

FR Wilk

[quote]Originally posted by chris luckett:
<strong>The generic Bosch sensors #s are:

3-wire heated: 003913
Single wire universal: 11051

Available at any local auto parts store.</strong><hr></blockquote>

Neither of these numbers are correct. The 003913 is not a valid BOSCH part number. The 11051 is a VW/Audi part number and not the Universal part. It costs about $15 more than the Universal O2 Sensor.

BOSCH has 2 Universal Sensors for 1-wire unheated O2 sensors. Price is about $20.
11025
11027

BOSCH 13913 is commonly used as the 3-wire Universal Sensor. Price is about $40.

FR Wilk
<a href="http://944dme.tripod.com" target="_blank">http://944dme.tripod.com</a>
<a href="http://early944.tripod.com" target="_blank">http://early944.tripod.com</a>
8Þ
______________________________________________________
_

luckett

Hmm, those are the #s that were given out on the 924/944/968 mailing list by Clifton Hipsher, who seems to have a good understanding of the O2 sensors (along with FR Wilk, the resident electronic/DME guy).

Garbage in, garbage out.


[quote] BOSCH 13913 is commonly used as the 3-wire Universal Sensor.<hr></blockquote>

This is the 3-wire sensor that I have purchased in the past, and it comes with a connector for some other car (Ford?) that must be clipped off.

zucker,

Can you check to see if the 13913 is a suitable replacement for a 968? What is the "universal connector system" that you speak of?


FR Wilk,

Thanks for correcting my mis-information.

newoldguy

Zucker,
Very interesting. I think we'd better ask you to elaborate some more. I like others I assume, cut off the plug that came on the universal sensor, and just butt spliced up the wires to the Porsche connector. So, if this is a mistake, what is the cure? What are we supposed to use? More info please especially re: air replenishment, etc.

For what its worth, I was able to easily remove my old sensor and put in the new by first spraying on a little PB Blaster, then using a 3/4's (yes, SAE) flare nut wrench to remove the old. Then put in new with a little anti-seize. I did this in the driveway with the front on jack stands. Mine is an '87 n/a. Cake.

zucker

When you buy a universal sensor they are supposed to give you a newly developed posilock sealed connector system. We have recently released these parts. There is a universal that has been released which is an ideal replacement for the 944/968 series vehicles. However it has not been cross referenced and sold for European applications. But what I can do is find what American vehicle the sensor is sold for and let you know.
Basically I'll tell you (Monday or Tuesday) to go to your autoparts store and buy a universal for let's say a Ford Windstar and it will be the correct ceramic/heater and similiar protection tube and you will receive the universal connector system(patent pending).
I have done some work on this for my personal use so I will let the list know of my findings.
Myself and a buddy have already installed these sensors on our 968 and 951 respectively.
As far as air replenishment goes, inside the ceramic(thimble shape)is a chamber of reference air(ambient air) and a platinum conductor. During rich operation there is an abscence of air in the exhaust stream. This creates an oxygen gradient across the ceramic. On the outside of the ceramic is another platinum conductor(power grid - Bosch patent)the gradient causes ionic conductivity across the zirconia(ceramic).If the sensor was in ambient air and was at operating temperature the voltage output would be approx. 0 volts.

Skip

This would be very interesting information to be aware of. As far as I know, the universal replacements for all cars are prescribed by Bosch AG. They are not chosen at will, or in random, by the aftermarket. If in fact there is a more sutiable replacement, and in fact there may be an inadequacy discovered with the current prescribed replacements - that would be the subject of a formal change from Robert Bosch GmbH - I assume. Please keep us all informed of your findings, and many thanks for your interest.

Skip

SteveB

Hey Zucker,
Thanks for all the very valuable and interesting information. This is exactly why I joined the List! Great technical stuff.

I have an '86 Porsche 944 Turbo and sent the original post asking about the O2 sensor.

What can you tell me about the correct replacement sensor and connector for my car.

Seems to be a real big difference in price between a Porsche O2 sensor ($180) and a Bosch universal 3-wire ($40).

Thanks so much, look forward to your response.
Steve
'86 951 (and running rich)