1994 320i Oxygen sensor - United Bimmer Community

**Yosuf123** · 02-27-2008, 04:50 PM

Hello

I have a 1994 320i (Canadian Model). My oxygen sensor needs to be replaced because I keep failing the emissions test.

I wanted to know if anyone knows what kind of O2 sensor my car takes (2 wire, 3 wire, etc.).

I have called the American dealers and a few Canadian dealers and they have been no help.

I am looking to purchase after market parts because they are cheaper. If anyone could help me that would be greatly appreciated.

**JetBlack328i** · 02-28-2008, 12:37 AM

I have a 96 328i and the oxygen sensors have two wires you can climb under the car and look at them to tell..

**Maxi** · 02-28-2008, 03:59 AM

Just take a look at the plug of it. and see how many pin there.

good luck,

**H3-2.1** · 02-28-2008, 09:15 AM

What is the production date? month/year? automatic or manual transmission?

Cheers,

**Danucksjoe** · 02-28-2008, 01:10 PM

Quote:

Originally Posted by Yosuf123

.....I wanted to know if anyone knows what kind of O2 sensor my car takes (2 wire, 3 wire, etc.). ......

Four wires, pre-cat......but don't bother

If you failed emissions buying an after market one will not help you. O2 sensors like everything else in life are proprietary and carry patents. Although all O2 sensors do the same thing, adjust the air fuel mixture, they all do it slightly different and as such are engine specific. It's true that using a universal one or one that isn't designed for the specific engine WILL NOT trigger the Check Engine Light but it is equally true that it will not adjust the air fuel ratio properly. This is because the Onboard Diagnostics do not check to see if the sensors are the correct ones, (that's the mechanics job) they check to ensure the sensor is not faulting.

Most O2 sensors adjust the mixture by adjusting a voltage span of 1 volt. The computer adjusts the air fuel mixture according to the signal it receives from the O2 sensor to try and produce the 14.7 : 1 stoich mixture. This is where the engine specific comes into play. What voltage to get this mixture is the part that is slightly different for different sensors and is the part that is patent locked.

For example, let's suppose a specific Ford sensor looks and fits a BMW application. This sensor may send a voltage of 4.8 volts when it senses the stoich A/F ratio. The BMW DME is not calibrated for 4.8 volts to achieve the stoich A/F ratio. It may be calibrated to 5.2 volts to achieve it, anything else will either cause the DME to inject too much fuel or not enough fuel causing rich or lean conditions.

Again, this will not trigger the CEL to illuminate since the OBD's role is to check for faults in the sensor. You may think to yourself, "well it's only 1/3 of a volt, it shouldn't be a big deal" Remember, the entire span of the O2 sensor is 1 volt. In this 1 volt span, the car may not run because it is way too rich, or it's way too lean. So 1/3 volt is a big deal.

Aftermarket products cannot be identical to OEM products....they can perform similar actions but not be identical.

If you're from the Lower Mainland BC like I am, then I can save you the work of trial and error and tell you now, ICBC will not pass you if you use anything but the OEM sensor. Emissions level will not be the same. Been there, done that, bought the T-shirt.

After first using a Ford Econoline sensor, I failed.

Changed to the Bosch Universal, I failed.

Finally caved in and paid the $225 + labour to BMW and

I pass. Of course my knowledge on the subject was very limited at the time so I went to an indy shop first who suggested the O2 sensors and finally went to the dealership who explained it better.

Good Luck

**Yosuf123** · 02-28-2008, 02:15 PM

Hey thanks for all the info, my car is a manual (the only way to go). I called the dealership and they said it was $350!! Which at this point in time in my life is a lot because I just had a son 3 months ago and he goes through a ton of diapers.

Plus I live in Washington state now and would have to order the part from Canada.

What to do.....what to do????

**Danucksjoe** · 02-28-2008, 03:54 PM

Quote:

Originally Posted by Yosuf123

Hey thanks for all the info, my car is a manual (the only way to go). I called the dealership and they said it was $350!! Which at this point in time in my life is a lot because I just had a son 3 months ago and he goes through a ton of diapers.

Plus I live in Washington state now and would have to order the part from Canada.

What to do.....what to do????

If you live in the states now, order an OEM part from Pelican Parts and install it yourself.

http://www.pelicanparts.com/BMW/cata...pg4.htm#item25

**mullethunter3** · 02-28-2008, 03:59 PM

Dude, calm down. Here's what you should do:
1) Find the part on Pelican Parts
2) Call BavAuto (800)535-2002 and get a price match of the BOSCH sensor - BavAuto has 1000x better customer service than Pelican, trust me, I've been down both roads numerous times.
3) Wait for it to come in
4) Jack up car, crawl under
5) Replace O2 sensor, should be a 22mm if I remember correctly
6) Disconnect battery to clear codes, wait, then connect battery
7) Start car, should be no fault codes.
8) There, easy as pie.

**Yosuf123** · 02-28-2008, 05:08 PM

Hey Thanks for all the help I appreciate it a lot. I'm trying not to seem like a real dumb ass here but I went to pelican parts and they don't have an O2 sensor for 320i, would a 318i or 325i sensor work for my 320i??

**Danucksjoe** · 02-28-2008, 05:19 PM

Quote:

Originally Posted by Yosuf123

Hey Thanks for all the help I appreciate it a lot. I'm trying not to seem like a real dumb ass here but I went to pelican parts and they don't have an O2 sensor for 320i, would a 318i or 325i sensor work for my 320i??

realoem.com and have the last 7 digits of your VIN...you'll get the exact part for the car.