O2 Sensor Keeps needing replacement

[Camnyc]

Originally Posted by Stk08E90M3

Thank you to all for the replies. This one goes down in the record books. After working with 3 separate shops the cause was isolated to the DME and the voltage distribution box that sits between the alternator/battery power and the DME. The DME had corrosion present and the O2 heater circuit was reading 4.5v when the fuse that controls the O2 heater circuit was removed (yes, removed). A parasitic connection within the DME and was part of the problem. Secondarily, the voltage distributor box that regulates power into the DME was spiking when a constant level of power should have been observed. DME failure on E90/92 M3's is exceptionally rare. Voltage distributor box failures are common and this part is spread across many BMW models. Hopefully this post helps the community.

Did you have a code for all o2 sensors or just one? And did simply replacing the voltage distribution box fix the issue?

[Stk08E90M3]

I had 4 identical error codes; one for each of the O2 sensors. While the voltage distribution box should have been supplying a constant source power (and wasn't) the DME had developed a parasitic connection that had effectively created an alternate circuit within the DME. I suspect my problem was largely due to the parasitic connection within the DME. The voltage distribution box was a minor cost (approx $300 installed) and worth correcting.

[Locksmythe]

Originally Posted by dpaul

If you are getting O2 heater codes on all four sensors, take a look at fuse F76 (build date 08/2007 and before) or fuse F11 (build date 09/2007 and after).

All four heaters are supplied by this 20A fuse. It's in the junction box fuse panel under the glove box

https://www.newtis.info/tisv2/a/en/e90-m3-lim/i3MQHFP

Coming back to this thread three years later as I now have the heater error on all 4 (272c 272dm 273e 273f) and I pulled fuse 11 as you suggested and it does look like it may have burned out. I will go buy a new one (or a box!), but I suspect there is probably another problem that caused the fuse to blow. Hopefully not the DME issue, but I have been chasing electrical demons so it is possible.

[SHADY1]

Originally Posted by SHADY1

The gas mileage was not good when I had the first set of codes.

P0037: HO2S Heater Control Circuit Low Bank 1 Sensor 2
P0057: HO2S Heater Control Circuit Low Bank 2 Sensor 2
P0030: HO2S Heater Control Circuit Bank 1 Sensor 1
P0050: HO2S Heater Control Circuit Bank 2 Sensor 1

These faults are no longer there.

The new faults:

273F: DME Oxygen sensor final stage diagnosis heater before cat converter, bank 2
272C: DME Oxygen sensor, output-stage diagnosis heater behind cat bank 1
273E: DME Oxgen sensor final stage diagnosis heater before cat converter bank 1
272D: DME Oxygen sensor output-stage diagnosis heater behind cat bank 2

These new faults are not effecting the fuel mileage I can even clear this code and it stays gone until I turn the car off and then turn it back on the code is immediately there: service engine soon, increased emissions

This is the crazy thing that is killing me that it is a heat control issue I don't know what is causing this fault. My Headers are not causing a heat issue the few other people I know with headers are not having this problem.




No faults with the headers bro nothing is loose. What ever is causing the O2 sensor heat control has to be some type of sensor. It don't matter if the car is hot or cold this fault is getting on my last nerve at the moment

The problem I had was bad O2 sensors after I replaced them. Don't buy O2 sensors from a local Auto Part store. They might have the cheap BOSCH knock offs . This is what happened to me. I finally got tired of the codes went to the Stealership and bought real BOSCH 02 Sensors at Stealership price $$$. This fixed my problem. The next time I needed to buy O2 sensors again I did not go to the Stealership route again and pay $200+ each .

I ordered them off of ECS Tuning web site. They have 2 versions the Genuine BMW version $200+ each and the BOSCH version. at $100+ dollars each. They are the exact same O2 sensor. One you are paying the BMW tax and the other is the actual maker BOSCH be smart and get the BOSCH version. The BOSCH version are working like a Charm .

[SilverSlug]

Originally Posted by tokic_o

I got the engine light with "Increased Emissions" recently and the code was to replace the left bank O2 sensor. Got my mechanic to replace it with OEM part I got from the dealer. After 1-2 days of occasional driving the light comes back on and is for the O2 sensor again!! WTF?!?!?! Now my mechanic doesn't know wtf is going on because we just replaced the sensor but the light + increased emissions keeps coming back....

Anyone have this experience and know wtf is wrong? I prefer not to go to the dealer because I'd like to be able to find out the actual issue first.

Most likely one (or both) valve/s of the secondary air pumps is getting stuck open (or closed), causing the Increased Emissions code.

The valves get filled with water after the exhaust air condenses.

I have this too sometimes, but the more I drive the car, the less frequent it's there. This doesn't affect drivability (although annoying af), some people just code out the secondary air altogether to get ride of this.

Do you hear a water slurping sound at all in the engine?