What are normal MAF, Fuel Trim, O2 Readings for 3.0i

[upallnight]

Originally Posted by btrvalik

What are normal reading from these sensors using a tool the Torque Pro? I'm trying to diagnose a P1092 code. A local Indy shop said I needed a new MAF and new primary oxygen sensors. They also said my MAF went bad because I'm running a K&N and they got BMW code for fuel trim errors. They also performed a smoke test and found no leaks.

From the report:

TECHNICIAN NOTES:Faults stored for bank 1 oxygen sensor trimming.
Multiplicative values are extremely
high.
Performed intake system smoke test and found no leaks.
Found K&N air filter to be installed on
vehicle.
Recommend replacement of air mass meter and both primary o2 sensors with a new
OE air filter at this time.

When I talked to Bavarian Auto they said MAF was unlikely and said I should replace the CCV / oil separator.

I have a 2005 with 109K miles - the rub is that the car runs perfectly just a stupid light.

Yesterday I replaced the primary O2, new plugs, cleaned the MAF with MAF cleaner. As most know, the CCV rebuild is rather involved - not the most fun job for winter time - for now, I'm holding off or may need to get a shop to do it - I would like to replace it once spring hits since it is way overdue according to what I've read. A day or so before I got a light, I did hear a strange whistling sound on a cold day - another possible CCV clue. After the tune-up, the car seems even more smooth - but it's hard to tell - a bit like how the car seems faster after washing and waxing all day

The easy next step, would be to replace the MAF and hope for the best - but that approach rarely works. If I look at my MAF values reported in Torque, the graph makes sense to me - gradual smooth rise off idle, drops with gear change, then ramps, then drops if I let off the gas. The display lags by a second or two, but I assume that is due to the ODBII, Bluetooth, app, display.

I wish I had some baseline measures - I would appreciate if folks could post their readings for cars with no codes etc


Sent from my iPad using Tapatalk

Lose the boy racer CAI. CAI doesn't do anything for a X5 or a M54 engine.

Here's a reason why you need to lose the CAI.

https://www.youtube.com/watch?v=FXT49BMxCOg&t=911s

[btrvalik]

The car goes into closed loop within the first min or two of running, so most of it is closed loop - as reported by torque. I don't have a CAI - I have a K&N in the factory airbox - it's been installed for a good 11 years - probably could have been clean a bit more frequently so I did a good MAF cleaning - but it made no difference.

[upallnight]

Originally Posted by btrvalik

The car goes into closed loop within the first min or two of running, so most of it is closed loop - as reported by torque. I don't have a CAI - I have a K&N in the factory airbox - it's been installed for a good 11 years - probably could have been clean a bit more frequently so I did a good MAF cleaning - but it made no difference.

I clean the KN filter on my G35 every Spring before the driving season and re-oil the filter.

I made a video from my Torque app of the X running.

Precat 02 sensors are on the left, Post cat sensors are on the right. As you can see, the post cat sensor shows a constant voltage.

Bank 1 is at the bottom of the screen and bank 2 is at the top. At the right is the MAF flow rate in g/s and the rev counter for the engine.

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

Hope this help.

[btrvalik]

Thanks for posting this.. It's good to see data from another X. When I look at these live displays in TorquePro, they are much smoother for me also - not dead flat like your. If it's not too much trouble, would you be willing to log data to a csv file: maf, 02s, trims, and rpm while driving to work or errands? maybe 15+ min of data? FYI, I initially had a hard time finding where this is configured - it's under the main screen - Settings->Data logging & upload->what to log – or something like that.

[upallnight]

Originally Posted by btrvalik

Thanks for posting this.. It's good to see data from another X. When I look at these live displays in TorquePro, they are much smoother for me also - not dead flat like your. If it's not too much trouble, would you be willing to log data to a csv file: maf, 02s, trims, and rpm while driving to work or errands? maybe 15+ min of data? FYI, I initially had a hard time finding where this is configured - it's under the main screen - Settings->Data logging & upload->what to log – or something like that.

Earliest that I will be able to log data is next weekend.

[Ricky Bobby]

Originally Posted by btrvalik

A day or so before I got a light, I did hear a strange whistling sound on a cold day - another possible CCV clue. After the tune-up, the car seems even more smooth - but it's hard to tell - a bit like how the car seems faster after washing and waxing all day

I don't know shit about the codes you are throwing but this is a telltale sign that your CCV is on borrowed time, if you get the whistling on a cold day before the car is up to temp -

Do the CCV system (updated dipstick guide tube as well) with cold weather parts (I prefer Genuine BMW) sooner rather than later, and clean your TB and ICV while it is out

[btrvalik]

I do need to replace my CCV due to age, but I'm not sure this is my problem - plus it's really cold to take on and extensive job. Here are a couple more test I tried:

The system was already smoke tested and found no leaks, as a test for vacuum leak

• Measure baseline vacuum (-13 PSI),
  Increase rpm to 2500 (momentary increase to -2)
  Back to baseline (-13 PSI) within ~20-30 sec

I then did a test to see what happens of I force it rich and then lean:

• Warm up the car with a drive
  Make it go rich at idle by turning on an unlit propane touch in front of the MAF
  Let it stabilize back to baseline
  Create a vacuum leak by removing oil cap

From the resulting plots, the system seems to respond properly[LIST]
ST fuel trims go to ~ -28 when propane is on
ST fuel trims return to the baseline when propane off
Open the oil filler
ST fuel trims go to ~ +20
Close cap
ST fuel trims go to back to baseline

The fuel trims and from side to side do roughly the same thing
Trying to decide if it's time to take the indy BMW shops advise and replace the MAF - hate throwing parts at the problem since the MAF seems to track RPM fairly well but not sure what else to try beyond doing the whole CCV, DISTA, ICV, etc

[btrvalik]

Originally Posted by 80stech

Looking at your earlier graphs you have to wonder why the long term trim reacts just as quickly as the short term ?? Is it maybe that "long term" isn't really the correct translation for that data and that is what's confusing everybody ?

My mistake - I added some additional data to my collection and it changed the column order - I had a longterm O2 on the bank 2 - now it's fixed.

[80stech]

Haha, I just deleted my post because when I looked at again I thought I had made a mistake!

[80stech]

Good to see that your posting this though!