Maf find help?

[spyderg0d]

2003 325i with Lean codes and open purge valve code... I noticed the maf readings has went lower than usual. Then i noticed it swayed while idle.. Went from 2.8g to 3g at times. Obviously the higher the maf went the lower my stf and ltf went.. So... I think my maf is bad... I Went to order maf at local advanced.. They cant get one even after the manager attempted to put me on a business account. Prod date of 7/03.. I have a 6 pin maf that has the rounded oval connector.. Realoem lists 4 maf numbers... What. The. Shit... Anyone have a definative part number and a store i can purchase thats not $250?.

[GreaseJunkie]

Try rockauto.com. They never fail me. And they have the best prices.

Sent from my U504TL using Tapatalk

[bluptgm3]

You are using the last seven of your VIN in www.realoem.com to drill in to the parts diagrams for specific part numbers?


Sent from my iPhone using Tapatalk

[MarcoZandrini]

What code reader are you using? What are codes that you’re getting? I’d fix the open purge valve first. Try disconnecting the purge valve’s electrical connector. I believe the valve is shut without power. Then I’d have the intake manifold professionally smoke tested as it sounds like you have vacuum leaks. Try www.bimrs.org to find a reputable indie shop that specializes in bimmers in your area. As far as a new MAF, buy a MAF made by Siemens/VDO from FCPEuro. Everything sold by FCPEuro carries a lifetime warranty! Do not buy a MAF made in China as they are crap.

[All2kool]

Anyone have a definative part number and a store i can purchase thats not $250?.

The MAF is one of those parts on your BMW that you never want to go cheap on. I suggest you replace it with an original Siemens/VDO unit. If that is not an option for you, a more affordable OEM brand would be Bremi. I've had a Bremi in the 2002 for quite some time now without any issue. I wouldn't suggest any other brands for a BMW.

[spyderg0d]

Just useing a bluetooth reader with some pay for app on my phone. This is the end of the road in a lean condition shpeal.. Ive been through the entire intake.. Its an impossibility to have a vac leak.. Every hose is new. Every mateing surface is tight and sealed with sealant. New gaskets in entirety. New cvv and hoses.
Im not new to bmw or mechanics in the slightest. Just an odd prod month during electronics shifts..
Yes, i used specifically my last 7 of vin to look up parts.. If you see aomething different than me on real oem.. Car is 07/03 325i sedan m54 auto... This car has the odd wide band 02 sensors with the square/oval plugs. The sap pump that sits above the headers with the secondary maf above as well... Its apperently an oddball for sure.

[RobertDenali]

If you are not new to BMW why are you buying a MAF at autozone?

You obviously want help from the forum. Get your smoke machine out and find the leak.

You might also want to check the idle control valve for build up.

[spyderg0d]

Mostly because they have warrenties.. And they dont take a week to ship. And 75% of the time the parts work fine for extended periods of time.. I want help from the forum getting me the right part # .
I checked icv when going through the intake gaskets andbinstalling new cvv.

[MarcoZandrini]

FCPEuro is located in that distant land called Connecticut. One day, two days max for shipping. Lifetime warranty on everything it sells.


BMW went to wide band oxygen sensors in model year 2003. So your sensors aren’t oddball. What codes are you getting?

[spyderg0d]

Lean codes for both banks.. Purge valve small leak then open circuit...
My ltf float around 11.7. Stft seem initially lean when accelerating, but are consistant at any rev Stft float around there at idle, and on driving.. Initially stft drop when accelerating, but level out on consistant speed to same as idle..
This all started after cvv freeze up... Twice... New hoses, new gaskets, new pipes, no cracks anywhere.. Disa is good.. I went through the entire intake twice to assure no leaks.. I rtv every single connection... It is 100% air tight.. I assured the hose on the fpr was tight as well.
My readings on my maf at a consistant 700 idle float from 2.8g to 3.0.. I noticed the lower my maf reads, the greater my trims go.. I read mafs read low when going bad. So... Here i am.. Trying to find a maf that reads right so i can get this annoying cel off.

[RobertDenali]

I have never heard of a maf from autozone operating properly but maybe yours is the first. I would return the maf and at minimum buy the original manufacturer of the bmw maf from a company such as fcpeuro, ECStuning etc.

You will never have a good baseline with cheap electronics for critical functions on these cars.

You typically have lean codes if your maf is operating incorrectly, you have a vacuum leak, bad O2s or fuel starvation issue. The DME will always be accurate on Stoichiometric Air-fuel Ratio if the aforementioned items are fine.

If you unplug your maf does the car idle properly?

When you checked the icv was the valve moving freely?

I edited my post to give you this site:


https://www.ecstuning.com/BMW-E46-32...Mass_Air_Flow/

I typically go there put in the car info then find the part number. Take that part number go to realoem.com and cross reference it to be 100% sure.

[spyderg0d]

I didnt purchase a maf from advanced auto.. Not auto zone.. But that doeant matter i guess.
If i unplug the maf (if it is bad) and there are no vac leaks, i should get a proper 02 sensor readings correct?

[RobertDenali]

Yes your O2s pre and post cats should read normal voltage and a typical check on MAFs is to remove the electrical connector and see if your idle normalizes.

[harrier]

Try rockauto.com. They never fail me. And they have the best prices.

Sent from my U504TL using Tapatalk

Good lord please don’t do this.

put your vin into real oem and get the right part number for the MAF

then buy VDO/Siemens MAF at FCPEuro with lifetime warranty. There is no cheap substitute (it has been tested)

get spark plugs at rock auto

and there is no surface on the intake that should have RTV - differential, valve cover, and oil pan/rear mains seal yes. Intake is all rubber seals, caps and hoses. You pull the manifold, replace every o-ring, hose, seal and cap, including the sap and solenoid lines and the fuel filter vacuum line. Then the o-rings for the dipstick.

replace your pre cat o2 sensors (Bosch) and MAF.

test your fuel pressure

I have done this over and over. You are not going to find some miracle new approach. It has been solved so many times.

[harrier]

Yes your O2s pre and post cats should read normal voltage and a typical check on MAFs is to remove the electrical connector and see if your idle normalizes.

and this test can help you tell you have a problem, but it is not a reliable MAF test.