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Old 04-11-2014, 05:17 PM   #21
jfoj
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Quote:
Originally Posted by pauly99 View Post
I didn't check the name stamped on the MAF sensor when I removed it to check the DISA valve but I am hoping the previous owner didn't put in cheap parts. The car feels like it is running smoother but the numbers don't reflect that. The LTFT was between 8.6% and 10.9% at idle once the car was warmed up and driven a few minutes ago. Nice having new rubber (boots) and a new F connector on there now though.

So per JFOJ, sounds like I should be checking my MAF sensor and O2 sensors. Can the O2 sensors be checked (values)?
Really no way to "check a MAF", there are some complicated ways to make a full throttle run, adjust for temp, humidity, barometric pressure and elevation but this may not yield solid results when finished.

Just because the MAF has the "proper" marking is by no means a guarantee that the MAF is legitimate and works properly.

Most high LTFT at idle are due to vacuum leaks. Everyone says they do not have any, believe me, there are PLENTY that are over looked. Smoke testing is usually the best way to located them. Also need to smoke test the crankcase as well.

O2 sensor are best tested from cold start and graphed, however, wideband sensors are a bit harder to graph/trend/fingerprint.

But usually if the O2 sensors are registering high percentage in the LTFT category, this almost always means the O2 sensors are in fact working.
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Old 04-19-2014, 01:08 PM   #22
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Replaced MAF. New figures.
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Old 05-03-2017, 01:31 PM   #23
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Maf

Hello to all,

Just recently my car (200 328ci with M54B30 intake manifold) was giving lean codes 9(OBD Fusion was rendering very high STFT and LTFT would not oscillate) and ended up finding several air leaks in the engine. One was the DISA valve o-ring, the air boot that connects to the throttle body and a thin vacuum hose that connects to the rear of the intake manifold. STFT's are now very low and my LTFT's are at 6.8 bank 1 and 9.4 bank 2.

Are these values still to high? I did not physically check the CCV valve hoses, but did see the CCV valve hose that connects to the oil dipstick and it looks good. The CCV and 4 hoses were replaced about 20K.

Car runs really good and idle is stronger than ever.

Should I be worrying about these values?

What else should I check?

I do know that the MAF on the car is one from a salvage yard as my mechanic mistakenly broke the one on my car and he ordered a used on through ebay several years ago. Might it be time to get a new MAF?

I cannot imagine I still have air leaks in the engine.

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Old 05-03-2017, 01:51 PM   #24
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LTFT values are still too high. At 9.4 on Bank #2 you are right at the tipping point with no headroom, you keep driving the car and you will get Lean code(s) again pretty quickly. This being said, if you have not driven the car for at least a week with the latest repairs, the Adaptations may not have fully adjusted yet.

The 2.5% difference between Banks, still seems that something may be wrong with Bank #2.

If the car has original Pre-cat O2 sensors, I would HIGHLY suggest these be replaced before the MAF. Since your O2 sensors are 4 wire non-Wideband sensors, the Bosch Direct Fit replacement sensors on Amazon are around $40 each last I checked which is a decent price. 4 wire O2 sensors should be replaced every 100k miles as the are consumable, almost every car I deal with has original O2 sensors still installed at 150-275kk miles!
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Old 05-03-2017, 01:57 PM   #25
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LTFT values are still too high. At 9.4 on Bank #2 you are right at the tipping point with no headroom, you keep driving the car and you will get Lean code(s) again pretty quickly. This being said, if you have not driven the car for at least a week with the latest repairs, the Adaptations may not have fully adjusted yet.



The 2.5% difference between Banks, still seems that something may be wrong with Bank #2.



If the car has original Pre-cat O2 sensors, I would HIGHLY suggest these be replaced before the MAF. Since your O2 sensors are 4 wire non-Wideband sensors, the Bosch Direct Fit replacement sensors on Amazon are around $40 each last I checked which is a decent price. 4 wire O2 sensors should be replaced every 100k miles as the are consumable, almost every car I deal with has original O2 sensors still installed at 150-275kk miles!


Car was fixed on monday and have been using it since. I will keep running it this week to see if adaptations set in

I did do one thing yesterday and that was increase fuel maps by 2% just to see what would happen. I noticed on my ride to work that STFT's went down a bit more as i observed the live data

I did not reset adaptations though when making the fuel maps changes. Should i reset adaptations and start from scratch?




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Old 05-03-2017, 02:07 PM   #26
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Car was fixed on monday and have been using it since. I will keep running it this week to see if adaptations set in

I did do one thing yesterday and that was increase fuel maps by 2% just to see what would happen. I noticed on my ride to work that STFT's went down a bit more as i observed the live data

I did not reset adaptations though when making the fuel maps changes. Should i reset adaptations and start from scratch?
How are you changing the Fuel Maps? Not sure this is a smart move, but there may be other things going on I am not aware of.

What resetting Adaptations is really for is so a repair shop can see immediately what the repair changed and if it was successful so the car does not need to be driven for 3-7 days over different driving conditions.

No harm resetting Adaptations, but it is not always necessary, it just saves time and will give you immediate gratification.
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Hidden OBC Menu - Check Voltage, Temp, Fuel Level - http://forum.e46fanatics.com/showthread.php?t=239619

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Old 05-03-2017, 02:28 PM   #27
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How are you changing the Fuel Maps? Not sure this is a smart move, but there may be other things going on I am not aware of.



What resetting Adaptations is really for is so a repair shop can see immediately what the repair changed and if it was successful so the car does not need to be driven for 3-7 days over different driving conditions.



No harm resetting Adaptations, but it is not always necessary, it just saves time and will give you immediate gratification.


I edited my tune with romraider software. My car has a full magnaflow exhaust/headers and M54B30 intake manifold. The tune has very light fuel map adjustments but out of curiosity i went ahead and added 2% across the maps except for the idle areas

STFT's as i was driving to work were running between low negative values (-1.6) and upon slight acceleration 3-5% positive, contrary to yesterday where i saw values in 6-7% positive

LTFT takes a bit to adapt so i will need to put in some extra miles to see what happens

Surprisingly how the engine runs so smooth and strong to have to keep looking for another bad part or some sort of leak


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Old 05-03-2017, 02:36 PM   #28
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Tweaking the fuel Map will often mask other problems, but if I followed what you indicated, that you did not tweak the idle fuel Map?

Not sure the intake change or even the headers would require much tweaking because additional airflow should be corrected by the MAF assuming it is only a small percentage.

Anyway, good luck with this, sometimes playing with software may not always be a solution but more of a bandaid depending on what is going on.
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Hidden OBC Menu - Check Voltage, Temp, Fuel Level - http://forum.e46fanatics.com/showthread.php?t=239619

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Old 05-03-2017, 02:39 PM   #29
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Tweaking the fuel Map will often mask other problems, but if I followed what you indicated, that you did not tweak the idle fuel Map?



Not sure the intake change or even the headers would require much tweaking because additional airflow should be corrected by the MAF assuming it is only a small percentage.



Anyway, good luck with this, sometimes playing with software may not always be a solution but more of a bandaid depending on what is going on.


Yes that is true. I just did it to see what would happen with regards to getting my engine fully corrected of any problems. At this moment, i would love to have a good MAF to test on the car

What is a proper maf reading for an M52TUB28, warm at idle?


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Old 05-03-2017, 02:40 PM   #30
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Really no way to "check a MAF"
One of our Professional Senior Members (PSM) from 2008 (What was I or anyone else doing in 2008? Damn time flies) wrote this thread. It may be of help to the OP:

http://forum.e46fanatics.com/showthread.php?p=8718211
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Old 05-03-2017, 02:41 PM   #31
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By the way what ever happened to JB? Good guy. Miss that member! Haven't seen him around for a good what.. 7- 8 years?
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Old 05-03-2017, 02:44 PM   #32
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Originally Posted by Mango View Post
One of our Professional Senior Members (PSM) from 2008 (What was I or anyone else doing in 2008? Damn time flies) wrote this thread. It may be of help to the OP:

http://forum.e46fanatics.com/showthread.php?p=8718211
It may be of help but based on experience trying to use these types of test, when the senor is degraded by under 15% there are often too many larger variables in this testing and often people come to the conclusion the MAF is good when it is not.

The MAF is the single most sensitive and critical sensor for a modern internal combustion engine and they do not last for ever. Like most sensors, they degrade over time in small amounts and usually a degraded MAF under reports.
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Old 05-03-2017, 03:27 PM   #33
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It may be of help but based on experience trying to use these types of test, when the senor is degraded by under 15% there are often too many larger variables in this testing and often people come to the conclusion the MAF is good when it is not.



The MAF is the single most sensitive and critical sensor for a modern internal combustion engine and they do not last for ever. Like most sensors, they degrade over time in small amounts and usually a degraded MAF under reports.


I think might be a good investment to purchase a new maf I keep getting that feeling its the MAF that needs to be replaced. Will do good to the performance of the engine if its not the culprit of this fuel trim issue


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Old 05-03-2017, 03:31 PM   #34
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One of our Professional Senior Members (PSM) from 2008 (What was I or anyone else doing in 2008? Damn time flies) wrote this thread. It may be of help to the OP:



http://forum.e46fanatics.com/showthread.php?p=8718211


Thanks Mango

Will check it out


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Old 05-03-2017, 04:23 PM   #35
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Thanks Mango

Will check it out


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Old 05-03-2017, 04:35 PM   #36
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My car has just over 82k and is in pristine condition. I will give him the gift of a new Siemens MAF.

Any place to get a real good deal on one?


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Old 05-03-2017, 05:54 PM   #37
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2 of your friends:

www.realoem.com & www.bmwpnpc.com

I find that oembimmerparts.com has quality products at good prices, but FCPEuro and BMAParts are other good options.
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Old 05-03-2017, 06:06 PM   #38
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If you've got an older e46, search for the Hyundai MAF for the Sonata.
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Old 05-03-2017, 06:43 PM   #39
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http://forum.e46fanatics.com/showthread.php?t=783659

http://forum.e46fanatics.com/showpos...3&postcount=17
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Old 05-04-2017, 08:51 AM   #40
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Hello to all

Just to update. When i got home yesterday i popped the hood and saw the plastic tube that connects to the throttle air boot had slightly come off

I fixed it and reloaded my tune without the 2% fuel increase and reset adaptations

This morning i noticed really high STFT's (5,7,12,18,21) and LTFT for bank 1 is at 0.8 and LTFT for bank 2 stays at 9.4

Is it normal for STFT values to fluctuate so greatly when starting a new cycle since i reset adaptations?


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