should I have an oxygen sensor??

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pierce
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Post Fri Jun 05, 2015 12:24 pm

My 89 325 doesn't have a lambda fitted, it has the plug for one, but just has a blank fitted. Also theres no heater relay fitted.

Should I fit a relay and lambda? Does the car even need one? If it left the factory without one, will the ecu be able to recognise that I have fitted one?

I understand the car should run a lot better with one fitted, just want to make sure I won't confuse the car when i plug one in.

(would be great if someone is able to clear up what cars / what year cars are fitted with a lambda and which aren't, as I've seen a few threads with confused e30 owners as to why theres not one fitted)

cheers
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jmc330i
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Post Fri Jun 05, 2015 12:43 pm

It's possible an '89 325i may of been specced by the buyer with a catalytic converter (and therefore a lambda sensor) from new, but as yours has the blank fitted to the plug in the loom I'd say yours probably wasn't one of them.
Any E30 from '89 could of been ordered with a cat, but only post Aug '92 cars actually need them for MOT purposes.

The sensor itself is only really there to control the fuel mixture and emissions to protect the cat, so unless you need to fit a cat for some strange reason, I wouldn't bother with the lambda sensor.
James
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'93 318i touring 16v
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Brianmoooore
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Post Fri Jun 05, 2015 1:28 pm

jmc330i wrote: but only post Aug '92 cars actually need them for MOT purposes.
Although any post Aug. '92 E30 fitted with a type of engine not originally fitted by BMW into that model (such as an M30 or M5x), a standard engine that was built before Aug. '92, a standard engine of indeterminate age, or an engine running on an alternative fuel, such as LPG also don't need a cat. for MOT emissions test.
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Post Fri Jun 05, 2015 2:16 pm

jmc330i wrote:The sensor itself is only really there to control the fuel mixture and emissions to protect the cat, so unless you need to fit a cat for some strange reason, I wouldn't bother with the lambda sensor.
Does it mean an m5x e30 doesn't need a lambda sensor to function properly or does that only apply to the older engines?

thanks,

JF
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Post Fri Jun 05, 2015 3:01 pm

Brianmoooore wrote:
jmc330i wrote: but only post Aug '92 cars actually need them for MOT purposes.
Although any post Aug. '92 E30 fitted with a type of engine not originally fitted by BMW into that model (such as an M30 or M5x), a standard engine that was built before Aug. '92, a standard engine of indeterminate age, or an engine running on an alternative fuel, such as LPG also don't need a cat. for MOT emissions test.
As the OP is talking about a standard E30, I didn't want complicate matters for him 8)
James
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'93 318i touring 16v
jmc330i
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Post Fri Jun 05, 2015 3:32 pm

JF008 wrote:
jmc330i wrote:The sensor itself is only really there to control the fuel mixture and emissions to protect the cat, so unless you need to fit a cat for some strange reason, I wouldn't bother with the lambda sensor.
Does it mean an m5x e30 doesn't need a lambda sensor to function properly or does that only apply to the older engines?

thanks,

JF
No, an M5x conversion will still need the lambda as the ECU will be expecting to see the signal from it.
A post '89 M20 (or M40) ECU can run with or without the lambda - those cars without the lambda sensor (most E30s) have a CO pot on the AFM to set the fuel mixture (done at the factory).
James
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'93 318i touring 16v
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pierce
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Post Fri Jun 05, 2015 4:44 pm

Thanks for the info guys!

To wrap things up, should I fit one? after reading this, I might not bother....

(I have no intention of fitting a cat)
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bosers
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Post Fri Jun 05, 2015 11:04 pm

You don't need one, I shouldn't bother mate. :)
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pierce
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Post Sun Jun 07, 2015 10:39 am

Thanks a lot guys.