M42club.com - Home of the BMW E30/E36 318i/iS
DISCUSSION => General Topics => Topic started by: mwilderl on June 07, 2011, 01:07:20 PM
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Is there a difference between the O2 sensor in the e30 and e36? I'm finishing up putting an m42 into my e21 and am getting ready to have an exhaust system put on. The only thing i saw was that the wire lengths are different.
Thanks! :)
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You will see that if you check on line parts suppliers that they are different.
The sensor is not based on body type ..E30 vs. E36 but on engine and year of engine. Compare part #s that should confirm the difference.
Buy the correct Oxygen Sensor.
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The sensors themselves are most likely identical. Most Bosch narrow-band O2 sensors behave identically. However, you SHOULD try to match up the O2 sensor to the ECU it was designed for. Between the different M42 cars though, the sensor should be interchangeable.
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alright, thanks! i guess i'll be getting the earlier model then, although i feel like i'm paying more for just another foot or so of wire.
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I heard that pre & post-cat models are different, but I have no solid evidence. Wire length and connector are definitely the only difference in a vast number of Bosch NB sensors.
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they make a universal one that works for a lot of BMW's that has an extra long harness to work on several models. its much cheaper than the m42 specific sensor. part # is 13108 (http://www.oreillyauto.com/site/c/detail/BOS0/13108.oap?keyword=oxygen&pt=02205&ppt=C0018)
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i read somewhere that you can use the cheap 25 dollar mustang O2 sensors and just splice them into the existing lines? any troof to this?
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Any Ford four-wire should work, most recent V8's have them installed pre-cat. They're the same Bosch sensor. I've heard the post-cat one is different, but I have no really solid proof off-hand for that.
I'd highly recommend soldered splices & heat shrink tubes for a reliable connection. Keep the splices at the end of the wire so that the exhaust heat won't weaken the solder joints.
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would a 91 have the O2 pre or post cat?
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on a e30, it is post. Not sure with e36.
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so what ECU you have determines whether it is pre or post? The m42 i have is in an e21 now
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All E30 O2 sensors are PRE-cat (as in installed UPSTREAM of the cat). Post-cat sensors were brought about by OBDII cars.
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All E30 O2 sensors are PRE-cat (as in installed UPSTREAM of the cat). Post-cat sensors were brought about by OBDII cars.
Oops, yes they are pre-cat. I was thinking pre and typing post. lol
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Alright, if the post cat O2s weren't introduced until OBDII then i think i will go for the cheaper m42 sensor. I don't have an old O2 sensor to steal the plug from and use a mustang O2 sensor so that option is out and i don't want to mess up the wires. Another thought I've been having is using a wide band sensor, but i'm not sure how much work and money that would take and at this point i really want to get my car back on the road.
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A wide-band O2 setup is cool to have, and isn't really too expensive. The Innovate LC-1 is like $200 with the controller & sensor. However, wiring is not exactly straightforward and how you ground it is absolutely CRUCIAL. I had my car running like crap for years until I figured out that it was due to a grounding issue. I can put up a how-to here since it is not all THAT complex.
Unless you will have some sort of need for a WB setup though, stick with a stock NB one.
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Might be setting up a turbo on there, i have a log manifold, turbo and intercooler along with some piping. NOt sure what the benifits of having a WB O2 is though.
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Might be setting up a turbo on there, i have a log manifold, turbo and intercooler along with some piping. NOt sure what the benifits of having a WB O2 is though.
In my understanding a narrow band sensor, i.e. regular O2 sensor, will operate more like and on/off switch in terms of detecting lean/rich operation. Whereas a wide band sensor will provide ECU inputs more akin to the operation of a rheostat, allowing more precise fuel metering and thus better power delivery. The benefit is that in turbo/supercharged settings you get safe metering of fuel without risking detonation, not to mention that the engine should not run as rich the way some poorly tuned cars run. If this isn't accurate I hope someone else will chime in.
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original ecu need narrow band signal input.
http://www.autometer.com/tech_faq_answer.aspx?sid=1&qid=48
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original ecu need narrow band signal input.
There are some wide band to narrow band converters available for this task, but I do not know if our Motronic will work well with them. Any one else have a wide band sensor with a stock ECU that can enlighten everyone?
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The basic description of narrow-band sensor output is that they are only accurate for exhaust gas mixtures from a stoichiometric burn (~14.7:1 A/F). In rich & lean conditions, there isn't a good way to pull exact A/F ratios because the exhaust gas temperature is not accounted for, which makes a difference. Hence, they can only be accurate for a very narrow range of A/F ratios. Wide-band sensors do account for temperature, allowing them to accurately read a wider range of A/F ratios.
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so it sounds like i need to get a NB sensor until i decide i should go to a standalone ecu?
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For the most part, yes. A WBO2 system really doesn't do anything for you with the stock ECU, unless you are trying to rig up a forced induction system with the stock ECU and larger injectors.
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Might happen at some point in the next year ;) but we all know how long these things really take... I might just go all out when i do turbo and go to a standalone.
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There are some wide band to narrow band converters available for this task, but I do not know if our Motronic will work well with them. Any one else have a wide band sensor with a stock ECU that can enlighten everyone?
I have Innovate LC1 for this task, works good.
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found a interesting thread.. right or wrong?
http://forums.bimmerforums.com/forum/showthread.php?t=788400