Unofficialbmw.com

[dale]

I just searched for this info for a friend and didn't find a post with all the info in one place, so here it is.

Note that the prices listed below are from a few years ago, but the Ford application of the Bosch parts should be about $100 less, just splice the wires.

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1-wire: L-Jet BMWs had this, just signal, grounded through the exhaust, 84-85 318i

3-wire: 1 signal(blk), 2 for heating circuit(both wht), Motronic 1.0 in 325e cars

4-wire: 1 signal(blk), 1 signal ground(gray), 2 for heating circuit(both wht), Motronic 1.1 in 325i cars

Info on O2 sensors
http://www.unofficialbmw.com/all/engine/all_o2sensor.html

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1987 E30 325E Sensor Bosch Part #13008 (3 Wire) $124.00
1989 E30 325I Sensor Bosch Part #13064 (4 Wire) $83.99
1990 Ford Mustang 5.0 Sensor Bosch Part #13942 (3 Wire) *$35.99*
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http://www.unofficialbmw.com/all/engine/all_o2_sensor_wiring.html
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FYI, on the 4 wire O2 harness,

The two white wires are the O2 sensor heater wires. Polarity is unimportant on these white wires.

The black wire is the O2 sensor voltage output signal wire. This is the signal that goes to the ECU.

The grey wire is a secondary ground. The O2 sensor is already grounded to the exhaust pipe by being screwed into the sensor bung hole. Best to ground the grey wire to the chassis instead of the exhaust pipe.

Ignore the main wire harness color codes. The main harness/O2 sensor connector plug design will keep the wires clocked correctly .......provided you match a 3 wire O2 sensor to a 3 wire main harness.

I've never actually done it before but I'm sure the ECU would be fried if battery voltage (12V) was accidently applied to the O2 voltage signal wire (in the main wire harness) leading TO the ECU. The O2 sensor generates only 1.1 volts max. (and a few milliamps). 12 volts (and hundreds of amps) applied to that circuit might turn that ECU circuit to toast.

There's plenty of text in the archived threads about buying a 3 wire (2 white wire, 1 black wire) O2 sensor for a '87-'92 Ford Mustang and using it in the E30 BMW's. The Bosch sensor probe itself is identical between the Ford and BMW. The difference being the wire harness connector AND about 100 bucks! The BMW sensor lists for ~$135. The Ford Mustang sensor lists for ~$38.95 at Auto Zone. Aren't we Bimmer owners special?

Cut the old BMW O2 sensor harness pigtail close to the sensor. Cut the Mustang O2 sensor harness pigtail close to the connector plug. Splice the two pigtail harness : white wires together (polarity unimportant) Remember, these are only sensor heater wires.

Now splice the single black wires together. The black wire is the O2 voltage signal that goes to the ECU. Insulate all splices.

Now, you have a spliced O2 pigtail harness with a new O2 sensor on one end and the old BMW wire harness connector on the other end and insulated wire splices somewhere in the middle. It's probably about 4-5' long! That's a bit long. Shorted it to about the same length as the original BMW sensor harness pigtail. You get the picture (and save a C Note).

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http://www.unofficialbmw.com/all/engine/all_cheap_o2_sensor.html

I received a great tip from a digester a few months ago. Allen from Simpsonville, SC, THANK YOU! Your suggestion for using the Bosch part that goes in a 5.0 liter 1990 Mustang works great on my big six. And wow what a difference in price. The local parts store wants only $39 for the Bosch part no. 13942 and then asked $132 for the part as it crossed to my BMW 535i. The sensor numbers were almost identical (off by the last digit of 1..ex..0258003008 vice 0258003009 for the new one). Better yet the sensors were identical except for the different wiring plug. Expensive plug folks!!! I just soldered the old plug onto the new sensor and everything worked great. My big six idles a little better too (it was running rich according to the black tail pipes). Response picked up and I'm hoping for better gas mileage. Once again I receive great tips from this digest...keep it up folks.

4. Regarding substitution, Bosch lists #13942 as its interchange for the Ford DY606 that others have recommended, and is cheaper. Cheaper still, and apparently identical to the 942 except for the connector which will be cut off anyway is 13913, whose original application was an 86 Taurus V-6, (I paid about $44 for it). This is even less than some of the kits available by mail order and given that the original application is as common as dirt, it should be in stock at any auto parts store in North America that sells Bosch. (BTW, both of these sensors appeared the same as my (literally) factory original at the tip, but the barrel was somewhat shorter) At this price, there is no reason not to change your sensor every 60,000 miles, which is Bosch's current recommendation, especially since you will get your money back in increased mileage fairly quickly- see below.

5. I notice an immediate increase of about 2-3 mpg after replacing the sensor.

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somewhere there must be an O2 sensor faq - including the part# of the Ford (made by Bobby Bosch) sensor I found that worked just fine with my '87 535i (big-six-engine). Dunno if your E30 would use the same one. The one I found is a DV505, 3 wire, heated Bosch sensor.. cost around $45 from Ford (vs $135 from BMW). Worked fine.

As far as the connector going bad - rare if ever. The sensor itself wears out, it depletes itself in operation, it goes kaput, toes up, dead, non-functional. Usual interval is around 50-70,000 miles which is why BMW recommends replacement at minimal 50k intervals.

To install the Ford sensor (if you have a three-wire) requires some minimal electronic capabilities, as well as the talent of telling black from white (there are three wires - if I remember right, two whites - heater wires, and a black signal wire.. or the other way around. Doesn't matter, hook white to white and black to black and it will work).

If your E30 uses a 'one-wire' sensor - there are even less expensive alternatives which will require you trundling off to an auto parts store and finding a universal 1 wire Bosch replacement (cost around $25).. I'm assuming you have the three wire given the BMW price you quoted.

BTW - if the parts dude at Ford gives you a hard time about DV505 (it could be "DY505" - brain fade), tell'em you want one for a 1987 Ford Mustang V8.. dat's the one.

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Subject: <E30> o2 sensor

I just purchased and oxygen sensor for my '88 325iC and have a question. I bought the sensor for a 1990 Mustang 5.0 V8 as others have suggested. However, this sensor has 3 wires (2 white and 1 black) while the one currently on my vehicle has four wires (2 white, 1 black and 1 grey). Is this the correct sensor do I just ignore the grey wire when I swap the connectors?
>>

I have the Mustang O2 sensor in my 86 E30 and also helped a friend put a Mustang O2 sensor in a 89 Volvo 740GL. Both cars were the three-wire type. Saved lots of money, $35 vs $150 and the only difference was the CONNECTOR!

I am pretty sure that the grey wire is only for shielding or grounding and will probably be OK if left un-connected. I have a Bimmer friend in Virginia who did exactly that with his E30 and his does just fine.

I have found that If you wish to solder the BMW connector on the Mustang O2 sensor it helps to REALLY scratch the wires until the copper shows. You see these wires are plated with some kind of shiney metal that doesn't take solder very well.

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Found some additional Bosch Parts:
Generic 4 wire Bosch O2 sensor 15725, designed to reuse your connection, about $45:

http://www.amazon.com/Bosch-15725-Oxygen-Universal-Fitment/dp/B000BZL07G/

Generic 3 wire Bosch 02 sensor 15726, about $43
http://www.amazon.com/gp/product/B000BZI4KC/

Generic 3 wire Bosch O2 sensor 15735, designed to reuse your connection, about $50:
http://www.amazon.com/Bosch-15735-Oxygen-Universal-Fitment/dp/B000BZI4L6

Generic 3 wire Bosch O2 sensor 15730, designed to reuse your connection, about $50:

http://www.amazon.com/Bosch-15730-Oxygen-Universal-Fitment/dp/B000BZL08A/

Generic 1 wire Bosch O2 sensor 11027, perfect for those early 318i cars, $17:
http://www.amazon.com/Bosch-11027-Oxygen-Universal-Fitment/dp/B0009IK7XI/

Bosch for Ford Mustang 13942, about $32
http://www.amazon.com/Bosch-13942-Oxygen-Sensor-Fitment/dp/B000BZG7NI/
_________________
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UnofficialBMW.com Webmaster
dale@unofficialbmw.com
sold in 2016
87 325 5spd eta

[tncean]

Dale; This 4 wire user appreciates the post. I just recently changed mine on my 90 325i and noticed an immediate gain in gas mileage.

Using the Ford model will save enough to buy some air filters. Next time.

tncean

[tncean]

Clarification requested. The Mustang sensor has 3 wires? The connector from the 90 325i has 4? The 4th wire from the car (gray?) is not used? Grounded?

Thanks

tncean

[dale]

You can use a 3 wire O2 sensor in a 4 wire application, I'd ground the grey wire to the chassis.

[tncean]

Thanks!

tncean

[dale]

Updated original post with links to Bosch Universal O2 sensors for sale at Amazon, and a link to the Ford Mustang one that is cheaper still at $32.
_________________
http://www.unofficialbmw.com
UnofficialBMW.com Webmaster
dale@unofficialbmw.com
sold in 2016
87 325 5spd eta

[Bimmerboy1989]

If a person wanted to go with the 4 wire for some reason, a bosch 15730 would do the trick.

[Bimmerboy1989]

Also a 15725 is a universal 3 wire. Both come with waterproof splices and are very easy to splice in.

[dale]

Looks like the prices of the Bosch direct application O2 sensors has come down a bit.

1987 325i $58
Bosch #13045
http://www.amazon.com/dp/B000BZG5SU

88-92 325i O2 sensor, $58
Bosch #13231
http://www.amazon.com/dp/B000BZG64S

The eta ones are still expensive though at $81
86-87 325e
Bosch #13008
http://www.amazon.com/dp/B000BZI0W4

This universal 3wire fits the 86-87 325e for $44
Bosch #15735
http://www.amazon.com/dp/B000BZI4L
_________________
http://www.unofficialbmw.com
UnofficialBMW.com Webmaster
dale@unofficialbmw.com
sold in 2016
87 325 5spd eta

[mik_meister_99]

How often does one recommend replacing the O2 sensor?
_________________
1988 325is 5-speed (Molly)
172k
You know you've got an e30 when you turn your radio up to mask valve clatter.

[magick]

Dale,

Thanks for the info, I just placed an order for the Oxygen sensor. Best price so far, compared to $122 on ebay for the eta.
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1985 325e

[dale]

How often to replace your O2 sensor? Somewhere between 60k and 100k miles. I think on our pre-95 cars, use 60k miles. If newer then 96, do it at 100k miles.

Dale
_________________
http://www.unofficialbmw.com
UnofficialBMW.com Webmaster
dale@unofficialbmw.com
sold in 2016
87 325 5spd eta

[robert1700]

I purchased a universal one and the replacement interval is 100K
_________________
1987 325i Convertible
51,000+ miles
Sold to a friend car is now destroyed, such a same.