E36 328 O2 sensor

[sclass]

Hi everyone,

Just found out why I have the Cat light permanently lit on the dash; the sensor wire is severed…! Car idles smoothly, never smokes, doesn’t hesitate on pull off or anything. Only the fuel consumption seems high (especially stop-start commuting). The best fuel consumption I get is around 9 – 9.5l/100km on long, steady speed trips…

A new lambda sensor costs A LOT (R3.7k) but is it still of consequence though if I’m going to decat the car? As I understand it, the ECU compares oxygen readings from the MAF and the O2 sensor, then it adjusts the fuel mixture accordingly. Then there’s something about the car operating in a closed loop and opened loop…but if there’s no Cat then what do I need the sensor for??? Or is there more to it than that?

What are my options fellas?

 

[P1000]

Fuel consumption will be bad until you replace the sensor. I think this will be a pre-cat sensor. Try to get the bosch part number and get it directly from them or diesel electric. Should not be that expensive.

 

[sclass]

Fuel consumption will be bad until you replace the sensor. I think this will be a pre-cat sensor. Try to get the bosch part number and get it directly from them or diesel electric. Should not be that expensive.

Thanks P1000, Realoem lists the O2 sensor as a Siemens unit though, does Diesel Electric supply all brands? Are you also saying this has no bearing on de-catting?

 

[mo_s]

good question...completely forgot about it..same thing with my 318is e36..oxygen sensor faulty..no warning light tho, but does log a fault..but never felt a difference on car wen driving..mech told me to leave it if I don wanna pay an arm and a leg for the O2 sensor..car is decatted and free flowed

 

[Raybimmer]

The o2 sensor is in the exhaust manifold , IIRC there is no other sensor later in the 328i exhaust system .Will have to check tomorrow .

 

[sclass]

Thanks Ray :thumbs:

 

[P1000]

The siemens models are problematic. You could try to find the Siemens part number for it and try importing it from the US, since lambda sensors are a dime a dozen over there. (try takealot.com, importitall.com, etc. given that you can find it on amazon.com). Oh, US sometimes has different part numbers to ours for the same thing, so you might need to spend some time on google. Just be cautious - the US models sometimes have different lambda sensors simply because of the RHD/LHD difference which means the cable length is different.

 

[Alister ///M]

i bought my 2 o2 sensors from pelican parts. came to R2400 landed. it was the ntk/siemens (the oem brand). i had called diesel electric to see if there was a bosch sensor for this car but they had no part number for it, so im guessing it they dont make it. theres a huge difference in power and economy after fitting them.

afaik the e36 328 euro models only came with two pre-cat sensors. (if any at all)

 

[sclass]

i bought my 2 o2 sensors from pelican parts. came to R2400 landed. it was the ntk/siemens (the oem brand). i had called diesel electric to see if there was a bosch sensor for this car but they had no part number for it, so im guessing it they dont make it. theres a huge difference in power and economy after fitting them.

afaik the e36 328 euro models only came with two pre-cat sensors. (if any at all)

Thanks Allister :thumbs:
Did you pay R2.4k for BOTH sensors?

I'm experiencing no running problems, but an improvement in fuel consumption is always welcome!

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The siemens models are problematic. You could try to find the Siemens part number for it and try importing it from the US, since lambda sensors are a dime a dozen over there. (try takealot.com, importitall.com, etc. given that you can find it on amazon.com). Oh, US sometimes has different part numbers to ours for the same thing, so you might need to spend some time on google. Just be cautious - the US models sometimes have different lambda sensors simply because of the RHD/LHD difference which means the cable length is different.

Eish, yah one has to be careful then. Are these sensors one of those things you have to replace in pairs?

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good question...completely forgot about it..same thing with my 318is e36..oxygen sensor faulty..no warning light tho, but does log a fault..but never felt a difference on car wen driving..mech told me to leave it if I don wanna pay an arm and a leg for the O2 sensor..car is decatted and free flowed

Aren't you worried about the car running lean? That's the only reason I'm keen to have this fitted even though the car's running fine. Or maybe this is more of an issue for an M54 engine or later...?

 

[Alister ///M]

yeah dude it was customs + 2 sensors + shipping = R2400
without the sensors your car wouldnt run lean, it would run a bit rich actually as the open loop maps are used. its mainly the maf that controls the fueling, the o2 sensors just "fine tune" the afr when in the closed loop range.

+1 what P1000 said, on my sensors the connectors were slightly different so i had to cut and fit some second hand ones i found, and yet i had the "correct" part numbers. but all worked out in the end. just have a look at your connector and see if its the same as the one you're buying.