M42 o2 Sensor - Where to buy?

[KenCopperwheat]

I know a lot of guys with M20s use Mustang O2 sensors and just solder the wires with the stock connector.

Is there a universal M42 O2 sensor? Or where is the cheapest place to get an OE one?

[P. Kennedy]

...Pelican lists a couple of different O2 sensors for the E30 318is, one of which is only $87. They also list one for around $130 which is also BMA's price. I don't want to spend three figures if I can help it, but I need a new one.

[P. Kennedy]

I misread the Pelican online catalog. They list one for the '91 318is for $118, which is still too much, but I may have to bite the bullet.

[hoevesruperd]

someone told me earlier on this forum that a bosch universal is a cheaper replacement
i think it consist of only the sensor that you connect to the old cable and plug
but i dont know where to get it or what part number it'd be

also interested in this, as i'm getting about 8mpg. (yes, its actually cheaper to run a tubo'd S54)

[Wise Old Dog]

8mpg, that sucks, you can probably see the gas coming out the tail pipe. No way is it burning it.
I have a universal Bosch. It's been a couple of years, but I think you just buy it according to how many wires it has, and then splice it. Thats what I did. I'm getting great mileage around town 27mpg, no highway miles.

[KenCopperwheat]

8mpg, that sucks, you can probably see the gas coming out the tail pipe. No way is it burning it.
I have a universal Bosch. It's been a couple of years, but I think you just buy it according to how many wires it has, and then splice it. Thats what I did. I'm getting great mileage around town 27mpg, no highway miles.

Where did you get the universal bosch one?

[bmwman91]

ANY 4-wire oxygen sensor will work, and if you are clever with wiring diagrams, so will a 3-wire. All narrow-band O2 sensors put out the same signal. If having the plug-n-play connector is worth an extra $80 to someone, go for it. If you want to do a little soldering & heat-shrink-tubing, save yourself some $$$! I can post up some wiring diagrams if needed.

[jrobie79]

id be interested in those wiring diagrams, where can i get the cheapest universal O2 sensor, either 3 or 4 wire, my dads an electrical engineer im sure he can figure out some way to wire it up or the diagram will help

[parker575]

Please post wiring diagrams and where I can find a standard 4-wire 02 sensor.

[Wise Old Dog]

IIRC I got it from an e-bay vendor and the instructions for the color coding are in the box. I figure somewhere on the web, there are numbers listed for the parts. Or the local parts store might have some info.

[parker575]

found one on ebay for $27 shipped.

[bmwman91]

Hokay.....

Relay circuitry:
http://www.e30tuner.com/assist/m42wdiag_p1.jpg

The O2 sensor itself. The sensor has a black, white, and 2 gray wires coming off of it. I cannot remember which is which, so just match their position to the connector pin #'s in the diagram when you look inside the connector body. Simple enough!
http://www.e30tuner.com/assist/m42wdiag_p4.jpg

[bmwman91]

THAT is why I recommend the Chilton's guide over the Bentley for the E30 318iS. It has this stuff at half the price. I have both manuals, and the Chilton's is every bit as capable with regard to this car (others not so much).

[parker575]

Installed the new o2 sensor. Spliced the wires and it works perfectly. My old one came off fairly easily, and it was pretty black around the base of the sensor but was white on the top. The car is clearly running better, however I don't think my mileage is back. After 65 miles the gauge is just under the 3/4 full mark. Is that normal? Should I run it through another emissions check to see if the hydrocarbons came down? Is there a chance I have an ECU issue?

[teh Phil]

Would this one (http://cgi.ebay.com/ebaymotors/NEW-BOSCH-UNIVERSAL-4-WIRE-OXYGEN-SENSOR-MERCEDES-BMW_W0QQcmdZViewItemQQcategoryZ33557QQihZ008QQitem Z180218210012QQrdZ1QQsspagenameZWDVW) work, or should I go for a more expensive one like this one (http://cgi.ebay.com/ebaymotors/Bosch-O2-Oxygen-Sensor-Universal-4-wire-15729_W0QQcmdZViewItemQQcategoryZ46097QQihZ003QQit emZ130200619098QQrdZ1QQsspagenameZWDVW) or this one (http://cgi.ebay.com/ebaymotors/Bosch-O2-Oxygen-Sensor-Universal-4-wire-15733_W0QQcmdZViewItemQQcategoryZ46097QQihZ003QQit emZ130200619088QQrdZ1QQsspagenameZWDVW)? 25 bucks seems a little too cheap for an O2 sensor! :eek:
-Phil

[tjts1]

After 65 miles the gauge is just under the 3/4 full mark.
I just went through the 3/4 mark at 117 miles (also 150,000 miles :D ). The fuel gauge is not linear.
Would this one (http://cgi.ebay.com/ebaymotors/NEW-BOSCH-UNIVERSAL-4-WIRE-OXYGEN-SENSOR-MERCEDES-BMW_W0QQcmdZViewItemQQcategoryZ33557QQihZ008QQitem Z180218210012QQrdZ1QQsspagenameZWDVW) work, or should I go for a more expensive one like this one (http://cgi.ebay.com/ebaymotors/Bosch-O2-Oxygen-Sensor-Universal-4-wire-15729_W0QQcmdZViewItemQQcategoryZ46097QQihZ003QQit emZ130200619098QQrdZ1QQsspagenameZWDVW) or this one (http://cgi.ebay.com/ebaymotors/Bosch-O2-Oxygen-Sensor-Universal-4-wire-15733_W0QQcmdZViewItemQQcategoryZ46097QQihZ003QQit emZ130200619088QQrdZ1QQsspagenameZWDVW)? 25 bucks seems a little too cheap for an O2 sensor! :eek:
-Phil
My cousin had a bad experience with an Ebay O2 sensor. Buy a universal at any auto parts store. Shouldn't cost much more.

[bmwman91]

I can usually get like 80 miles from the first 1/4 tank on the gauge. I would not really rely on the thing though. Just try to get a good idea of how many miles you can get from a tank & judge from there.

In the usual commute traffic, I try to fill up between 310 and 330 miles.

[Cobra Jet]

The universal O2's should work as stated above by others and the reason you can get them for less is purely due to the fact that the manufacturer is not including a connector on the end of the wires. You can easily make a universal work with any vehicle if you want to put a little time into:

A) taking apart the existing vehicle O2 connector plug (this can be done with MANY types of connectors), installing the proper new pins on the new universal O2's wire ends, then inserting those pins back into the vehicle's original O2 connector you had removed from the old O2 sensor

OR

B) take the old vehicle O2 sensor out, cut off the connector from it leaving approximately 3" of the old wire on the connector, grab your new universal O2, expose the wire from the wire casing on all wires (do the same on the connector you cut off the old O2), then splice together the wires from the new O2 and the old O2 connector and use either shrink wrap or electrical tape to cover the newly spliced joint.

I've never had issues using the BOSCH universal O2's in any vehicle. If you want to save money and put a little time in, the universal O2's will work.