[Johnny Tsunami]

I currently have a yellow service engine light on, which is preventing me to pass state inspection. I ran the OBII code reader and is getting the following codes; P0050, P0306, P0304, P3027, P0305, P0303. I'm guessing it is related to the oxygen sensor that needs to be replaced. Any ideas on how to reset the service engine light or would I have to replace the O2 sensor first to get the light to go away?

[BMWAddict2007]

You can clear any light if you have the right tools or have a shop do it. But it will keep coming back on until the problem is fixed

[mweisdorfer]

Originally Posted by Johnny Tsunami

I currently have a yellow service engine light on, which is preventing me to pass state inspection. I ran the OBII code reader and is getting the following codes; P0050, P0306, P0304, P3027, P0305, P0303. I'm guessing it is related to the oxygen sensor that needs to be replaced. Any ideas on how to reset the service engine light or would I have to replace the O2 sensor first to get the light to go away?

http://www.e90post.com/forums/showthread.php?t=357827

always replace o2 sensors in pairs.

[Greyfox]

First before replacing anything, clear the fault to see if it comes back.

Emission faults can from things like bad gas, loose fuel cap, etc.

Had some enterprising mechanics that would during emission tests in Northern Virginia would either read a fault or create one and then fail the vehicle.... then charge the person anywhere from $1500 to $4000 for the repair. Which tended to be just clearing the fault.

[tcphoto]

You can clear the codes, do homework on the specific codes because they will need to be resolved before it will pass inspection. They will still be there even if you clear them and the inspection will show them as pending. Either way, the issues will have to be addressed.

[Corno_Baldwin]

Not sure how the heater circuit is on these cars for the O2 - if it is fused or not. Make sure you check your circuit before just throwing an oxygen sensor at it. Could be as simple as a fuse for the O2 heater circuit.

[mweisdorfer]

Originally Posted by Johnny Tsunami

I currently have a yellow service engine light on, which is preventing me to pass state inspection. I ran the OBII code reader and is getting the following codes; P0050, P0306, P0304, P3027, P0305, P0303. I'm guessing it is related to the oxygen sensor that needs to be replaced. Any ideas on how to reset the service engine light or would I have to replace the O2 sensor first to get the light to go away?

If you drive a 328, the o2 sensors you need are right on top. Fairly easy to get to with the right tools. If you drive a 335i, its a little more involved, but not impossible. There are DIY's on this forum for both.

The two rear 02's (post-cat) just check to make sure the two front O2's are doing their job (Pre-cat). The most common culprit is the pre-cat's. I have 133k on my 335i and have never changed the post cat 02's.

[Johnny Tsunami]

I cleared all codes. Only code P0050 remains, which is dealing with bank 2 sensor 1 O2 sensor. I plan to clean it over the weekend to see if the codes clear and service engine light disappears. If doesn't clear, I am going to replace the entire O2 sensor.

[Wires]

There is nothing to "clean" on an O2 sensor. The car is 8 years old, the sensor is dead, just swap it.

It has a perpetual heater that runs to keep it at constant temperature. Stuff like that doesn't run forever.

[5tony]

Originally Posted by Wires

There is nothing to "clean" on an O2 sensor. The car is 8 years old, the sensor is dead, just swap it.

It has a perpetual heater that runs to keep it at constant temperature. Stuff like that doesn't run forever.

Agree. The heater circuit is part of the sensor and wiring itself. Just replace the precat sensor. Might as well do both while you're at it. The other one is likely to fail soon too.

[Efthreeoh]

Originally Posted by mweisdorfer

http://www.e90post.com/forums/showthread.php?t=357827

always replace o2 sensors in pairs.

I disagree. I lost the Bank 2 Sensor 1 (O2 sensor) on my N52 at 121,000. I replaced it. I'm now at 315,000 with the three other original sensors (okay I just jinxed myself...)

OP, I did a DIY to replace the exact same sensor that failed on your car. You need to pull the cabin airfilter housing and the engine cover to get to the end of the harness where the connector is.

http://www.e90post.com/forums/showthread.php?t=459104