[dekaykim]

Hi everyone.

First of all, I have to thank every single member of this community that posted threads before, which tremendously helped me in maintaining my 2001 ML320.

My question is about MAF sensor.

My car has Check Engine light on, and the OBDII scan result reads P0170 and P0173. By the way, the car runs well without any noticeable problems such as misfire etc.

I figured that the most common reason for this code MAF sensor, so I replaced it with the one that I bought from the following link:

98 99 00 01 02 03 04 05 Mercedes benz mass Air Flow c280 e320 ml320 meter 0280217515 1120940048 | AutoPartPro

I doubted why this brand new item is so well priced (around 70 including shipping), but I decided to give it a shot.

The fuel mileage of the car, I feel, became a little better after replacement, but the Check Engine light came on again after around 20 miles of driving.

My questions are as follows:

1. Shoud I believe this seller and this product? (They say it is brand new bosch one). If not, please recommend me a part dealers in east coast area (I live in DC area)

2. What other possible reasons for the code P0170 and P0173? People say that these code are "99%" due to malfunction of MAF sensor and I really do not think I am the 1% unlucky, but just is case.

Thanks in advance for your advice!

DK

 

[FAR888]

You may have purchased a non-genuine Bosch Mass Airflow Sensor (MAF).

This thread should make interesting reading:

http://www.benzworld.org/forums/w163-m-class/1364276-maf-sensor-alert.html

 

[dekaykim]

Thanks

Yes. I guess I bought from the wrong place.

Thanks for the information.

I guess this helps informing and alerting other potential buyers of MAF sensor.

I will update once I get the new genuine bosch part and whether it resolves the problem.

Thanks again!

 

[dekaykim]

Update on MAF sensor replacement

Just to update the recent information

First of all, I confirmed from this parts dealer that the MAF sensor is "aftermarket brand new" item. The sealing of the sensor is not well finished as the other article discusses, so I guess this is the item that is refurbished somehow and come out to market with the label of "brand new."

I took this part out of my car since it did not work, and cleaned it with the sensor cleaner bought from Advance Auto Part. I reinstalled the sensor into my car, and amazingly and surprisingly the Check Engine Light went off for the next 80 miles.

On the day I finished running 80 miles with the cleaned aftermarket sensor, the brand new Bosch sensor that I ordered from the same part dealer arrived home and I replaced the cleaned sensor with new Bosch one. After driving 20 miles with the new Bosch sensor, the CEL went on again.

In the mean time, the Bosch sensor that the parts dealer claims to be brand new Bosch got its box seal already broken upon arrival. Thus, I suspect whether this item is really brand new. I am refunding this Bosch one. The sealing of the sensor was smooth btw. I am attaching the pictures of this Bosch sensor.

Anyhow, I re-replaced the Bosch sensor with the cleaned aftermarket one and drove ~30 miles today, and CEL went off and car runs perfectly.

To sum up, this experience was not pleasant at all even though I seem to have resolved the problem with ~$80 or so ($70 for aftermarket sensor and $10 for MAF cleaner. I did not count $120 Bosch sensor because I am refunding it). If I have the same problem again in future, I guess I will just buy the authentic brand new Bosch or M/B part. The failure of the brand new part (which you suspect the authenticity of) leads to so much guess and forum search. For those who will have the same problem in near future just like me, please bother to spend extra $100 or so to buy the authentic item. It will save your time and worries eventually

 

[Darkmann]

Just to update the recent information

...
To sum up, this experience was not pleasant at all even though I seem to have resolved the problem with ~$80 or so ($70 for aftermarket sensor and $10 for MAF cleaner. I did not count $120 Bosch sensor because I am refunding it). If I have the same problem again in future, I guess I will just buy the authentic brand new Bosch or M/B part. The failure of the brand new part (which you suspect the authenticity of) leads to so much guess and forum search. For those who will have the same problem in near future just like me, please bother to spend extra $100 or so to buy the authentic item. It will save your time and worries eventually

Good for you. FYI, you don't have to buy the entire MAF (body + sensor). All you really want is the sensor itself (which Bosch sells). You can unscrew the bad sensor off the body and replace it with the new one. Also, why didn't you try to clean your original MAF before embarking on his adventure? At least you now have two MAF, right?

 

[43sqd]

Good for you. FYI, you don't have to buy the entire MAF (body + sensor). All you really want is the sensor itself (which Bosch sells). You can unscrew the bad sensor off the body and replace it with the new one. Also, why didn't you try to clean your original MAF before embarking on his adventure? At least you now have two MAF, right?

Darkmann, this issue has been discussed a few times by myself and greggs210. Bosch does not sell the insert alone. Bosch only sells a MAF sensor with the entire housing. We have both made calls to Bosch and confirmed this fact. Any purchase of a Bosch MAF sensor insert only, is a knock-off, even if it is in a Bosch box (which is also a knock-off).

 

[Darkmann]

Darkmann, this issue has been discussed a few times by myself and greggs210. Bosch does not sell the insert alone. Bosch only sells a MAF sensor with the entire housing. We have both made calls to Bosch and confirmed this fact. Any purchase of a Bosch MAF sensor insert only, is a knock-off, even if it is in a Bosch box (which is also a knock-off).

Thanks for that info. They must have changed their policy from about 4 years ago.

 

[dekaykim]

Cleaning bosch sensor

Also, why didn't you try to clean your original MAF before embarking on his adventure? At least you now have two MAF, right?

I was also thinking about this method, and concluded that it's not worth being cleaned considering the obvious fact that the part is either used or refurbished (only claimed being brand new by the seller). So why not just use the one that at least work regardless whether it's Bosch or not.

Actually, I just moved from Texas to Virginia, and car inspection here is very very strict. I already paid $44.00 for the first inspection which I failed, and If I do not get this thing fixed by the end of this week, I will have to pay extra $44.00 for another inspection. Thus, the method of cleaning Bosch part is a little gamble to me now. I might try cleaning it after passing the inspection.

Thanks for the advice though!