Cocktail of 3.0i Trouble Codes - Where to Begin?

[richardb]

Hey all, hope you're well. I had a P1093 code on my X5 for many months. That's the pre-cat fuel trim too rich code. I replaced both pre-cat oxygen sensors and set of spark plugs with no resolution.

I read several posts about a faulty idle control valve being the source of this problem, so I installed a brand new one in a desperate attempt to clear the code. The original had 18X,XXX miles on it and was cleaned once before, so no harm in replacement at this mileage anyway.

Here's my current list of codes, where do I begin? Haha. Smoke tested the intake, no leaks found.

P0313
P0161
P1092
P0158
P0313 PD

Wondering if this is a bad bank 2 sensor 2 oxygen sensor.

Here's the car in question, out for a blizzard cruise the other week... https://youtu.be/5CFdYNxKsK4

[80stech]

Start with first code listed and work down.

[upallnight]

Are you able to view live data? Short term, long term, 02 sensor voltage, MAF airflow in g/s. I wouldn't be changing the 02 sensor before seeing what kind of live data they are reporting.

[upallnight]

https://www.youtube.com/watch?v=zyh_4SktmFM

[upallnight]

https://www.youtube.com/watch?v=WMSM7WAbBss

[Effduration]

Would you mind defining each code? I'd like to help, but I don't want to look them all up.

And I don't suppose you have a BMW-specific scanner? just P-codes?

Were all these codes there previously? or did they just pop up? Was it only P1093 previously?

[Overboost]

Check MAF g/s values first. Should be in the 3 g/s at idle with no additional power draws, i.e.: no AC, lights, radio, blower fan, etc. 4g/s is too high

Secondly check your fuel pressure, should be around 52 PI Max.

[richardb]

Originally Posted by Overboost

Check MAF g/s values first. Should be in the 3 g/s at idle with no additional power draws, i.e.: no AC, lights, radio, blower fan, etc. 4g/s is too high

Secondly check your fuel pressure, should be around 52 PI Max.

Here are the BMW trouble codes using the C310 tool:

99 Oyxgen-sensor voltage behind cat converter, bank 2
EB Trimming, oxygen sensor before cat converter, bank 1
BF Insufficient heat output, oxygen sensor behind cat converter, bank 2
F3 Misfire, cylinder 6
F2 Misfire, cylinder 5

Checked out the other readings:

Idling the car with lights on last night, voltage at air-mass flow sensor 0.9 V

Air mass reading 18kg/h while idling
Air mass reading 44 kg/h at 2,000 rpm
Air mass reading 55 kg/h at 2,600 rpm


Finally, the oxygen sensors:

Bank 1 before cat: voltage 0.11 to 0.76 V
Bank 2 before cat: voltage 0.11 to 0.76 V
Bank 1 after cat: voltage 0.11 to 0.76 V
Bank 2 after cat: voltage frozen at 0.58 to 0.59 V

Voltage appears static at the bank 2 oxygen sensor after the cat, when it should be fluctuating up and down like the other 3.

[richardb]

Additional info from the data stream:

adaptation, mixture, additive bank 1: -0.11 ms
adaptation, mixture, additive bank 2: -0.02 ms
adaptation, mixture, bank 1 multiplicative: 5.8%
adaptation, mixture, bank 2 multiplicative: 6.9%

[upallnight]

Originally Posted by richardb

Here are the BMW trouble codes using the C310 tool:

99 Oyxgen-sensor voltage behind cat converter, bank 2
EB Trimming, oxygen sensor before cat converter, bank 1
BF Insufficient heat output, oxygen sensor behind cat converter, bank 2
F3 Misfire, cylinder 6
F2 Misfire, cylinder 5

Checked out the other readings:

Idling the car with lights on last night, voltage at air-mass flow sensor 0.9 V

Air mass reading 18kg/h while idling
Air mass reading 44 kg/h at 2,000 rpm
Air mass reading 55 kg/h at 2,600 rpm


Finally, the oxygen sensors:

Bank 1 before cat: voltage 0.11 to 0.76 V
Bank 2 before cat: voltage 0.11 to 0.76 V
Bank 1 after cat: voltage 0.11 to 0.76 V
Bank 2 after cat: voltage frozen at 0.58 to 0.59 V

Voltage appears static at the bank 2 oxygen sensor after the cat, when it should be fluctuating up and down like the other 3.

Voltage should not be fluctuating wildly for 02 sensor after the cat. The fact that your 02 sensor is varying the voltage leads me to think you have a bad 02 sensor but at bank 1 not bank 2.

Also your MAF 18K/hour equates to 18,000/3600 = 5g/s. 5g/s at idle is kind of high so. If you look at the video I posted, my MAF g/s was 3.6g/s at 700 rpm.
I think your MAF is over-reporting the airflow through it and the computer is trying to compensate for this data pid. You can try cleaning the MAF with MAF cleaner, don't use carb cleaner and make sure it is dried before starting the engine. Don't buy a cheap MAF from eBay or Amazon. Better to go to a junkyard and buy a genuine Siemens MAF.