New MAF= engine stutter/hesitation
 

In a previous thread, I chronicled how both L+R Cat's were replaced and how the car needed a new MAF sensor.

after putting in the new MAF sensor, the car indicated no malfunctions and the autozone scanner showed no codes, however, the car now stuters/hesitates when accelerating.

I have performed at least 3 throttle resets to no avail. When using cruise control, it shows no problems. Only when controlling the throttle manually, do symptoms appear.

Mainly the car will simply stutter/hesitate at random intervals ranging from mild to highly noticeable.

With the old MAF sensor which pulled a P1370 and P1373 fuel trim error code, the car would simply retard the engine timing so it would not operate at full power.

Also, recently I changed the fuel filter as well. On the side that connects from the gas tank to the fuel filter, I may have crossed those two lines, but I highly doubt it given the drivability of the car prior to the MAF change though I may be wrong.

Any help/solutions welcome. Thanks guys!!!

I had some of he symptons that you just described, however they only happened when I was completely stopped, i.e. at a traffic light. I drive a 2001 C240 and when I would press on the gas the car would shutter and gasp for air, but it would never stall. I took it to the dealer and they found that I needed a new fuel pump, fuel filter and gasket.

If I were you, take it to the dealer and let them have it for the day to diagnose your car's problems.

How did you know you needed a MAF? Did you remove it and bench test it? Did you run without for a while and things improved? I woud say on the C-class, more often than not, fuel trim errors are caused by a vacuum leak, especially if the car is running rough.

So do this, disconnect the MAF and drive around. The car should behave pretty close to normal. If it's still running rough, then it's not the MAF, check for vacuum leaks. If it runs well without the MAF, it's defective or if you got in on ebay or in a yard sale it's the wrong one (VW/Audi MAF's by Bosch look identical, cost much less and are not the same by any means).

It could be a fuel pressure issue, just put a fuel pressure guage on the rail and check, should be about 3.8 bar or 50PSI. Fuel pressure issues would not give you fuel trim errors, it would give you P030x codes for misfires.

Hi,

The dealership told me I needed one via the Star Diagnosis tool. Plus, before it was throwing the fuel trim codes.

So I ordered the right part off of eBay, threw it in there, and thats when this hesitation/stutter started happening.

Before then, with the old MAF, the CEL was on, and the engine did not operate at full power.

Vacuum leak is my first call as well. Second is that maybe it's the wrong part or it's faulty .However, the new MAF removed all the codes.

I"m gonna run it w/o the MAF just like you said and see what happens.

well i'll be damned,

Ran the car w/ the MAF unplugged and it ran fine with NO hesitaton/stuttering.

Replugged it back in making sure the pins were making full contact, and back to the same old stuttering.

Did I get a defective part? I checked the part numbers and they matched up correctly. Anything else I should be aware of?

thanks,
Ben

Sorry Ben, you been MAF'ed. There's one guy on ebay that sells VW MAF's and tells people it works on MB and even tells you the correct MB part number but ships you an VW MAF. VW MAF works differently yet looks identical, connector is identical but will give you hesitation and stuttering. You are by far not the first to be taken by this guy, and probably won't be last.

Hopefully you kept the original MAF, so get some CRC MAF Sensor cleaner for $6, remove the insert from the MAF and clean the heck out of the tip where the wire is and put it back together and stick it in the car. See if there's anything you can do to get your money back on the ebay MAF. From my experience, MB service departments are not the most honerable and them telling you that you need a MAF is a very quick 10 minute few hundred bucks they make off you when you probably just needed a few squirts of MAF cleaner.

Hehe, on the assembly both the Bosch and MB part number matched up and it appears that no tampering has been done with the 5pt security torx. The seller says he'll ship out another one asap.

http://cgi.ebay.com/ebaymotors/ws/eB...m=160152511886

Yeah the Mercedes dealers are EXTREMELY honorable. They made me realize that buying and servicing a Mercedes-Benz is a privilege and an honor. $800 for the MAF sensor installed. $120 for air filters that i had swapped out not months before. I'm surprised that they didn't refuse to warranty the cats based on the Denso Iridium plugs I put in which are non Bosch.

Very odd, but 2 AutoZone's said they didn't carry MAF cleaner. I guess i'll just blast the **** out of it with compressed air for now. Anything else I can squirt on it like windex or glass cleaner?

Fudge, just gotta wait a few more days for hopefully the right part and hope that i'm not victimized.

Windex, haha, no Lemon Pledge. Seriously, it's a sensitive electronic element and you don't want to use anything that may leave a residue or harm the cicuit board in side. So the alternative is Tuner Cleaner you can get a Radio Shack. I got my CRC MAF sensor cleaner from a Pep Boys. The minimum wage stock boy probably won't know what you are talking about. Just go to the section that has the carb cleaners, brake cleaners and such and look for a rather large gray spray can that says CRC Mass Air Flow Sensor Cleaner. It's been known to look like this -

http://www.crcindustries.com/catalog...sers/05110.jpg

i had the same problem with an aftermarket MAF sensor, so i returned it and bought the expensive bosch one from the MB dealer and the hesitation stopped.

yup, I got MAF'ed. Learned a lesson here. The knockoff Chinese part didn't have a country of origin printed on it, nor did it say Bosch on it. After working with Japanese cars, instead of German cars which I ditched with my A3 Jetta VR6, I almost forgot Robert Bosch is the name to know.

Took it up the chute and spent $245 for the real deal, and now it runs like butter. used 2 bottles of techron with each consecutive fill up and she runs now like she did before close to $900 in parts and labor.

Carsoft Baby. That's the next purchase.

MAF-ed thru eBay...Don't make this mistake
 

I've been MAF-ed!!!!!!!!!!!!

I'm only writing this to STOP the next person from doing what I did. I read this post, was warned about getting MAF-ed from eBay MAF sensors, decided to save money, ignored the warnings and GOT MAF-ed. DON'T DO IT!

I have read this post (and others on here about MAFs) so many times but the thought of saving a few hundred dollars made me buy a MAF from eBay. I was getting trim errors at first, on both banks, so after reading this tread I went to buy MAF cleaner and sprayed the heck out of my old MAF. It did not work. I found a $90-ish dollar MAF on eBay by a seller with over thousands of feedback at 99%. I also called my local MB dealer and they wanted $450. So I bought the one from eBay (non-Bosch but matching numbers). At first all was well; even my CEL light went out. Then 3 months later I get the CEL again. I check and I got 2 codes; low volt at MAF and low volt at IAT. Now my car hesitates and even stalls at a red light. I even had a near accident happen b/c my car hesitated while I was trying to make a right turn on a red light. I got my old MAF back out...sprayed the heck out of it again and put it back in the car. HESITATION GONE!!!...CEL light for low volt at MAF and IAT....GONE!!!

CEL-s for too rich mixture (trim error) at both banks came back again!

Now I was sure that my MAF is broken and the eBay MAF is giving me problems. I sucked it up and paid for the $450 MAF at the local MB dealer. Now the car purrs and is full of life again. No more hesitation, no more CEL-s, no more stalls, and no more near accidents.

Lost $90-ish dollars ($94 I think) to the eBay seller (who wouldn't refund me my money b/c its been 3 mo.) to learn this lesson. When buying a MAF get original BOSCH part made for your car; if its through eBay, not BOSCH, and not specific to your car...DON'T BUY IT! I've just confirmed what everyone else was saying above the hard way.

Hope this stops another from being MAF-ed.

MAF at great price $$
 

All,
After a lot of research I found MB MAF sensors at a great price online, and its genuine MB part.
http://germanstar.net/MAF.htm

Hope this helps.

Dean:)

I'd run across that before, but the site doesn't list MAF inserts for newer vehicles. It lists early c230's and SLK's, but also doesn't specify the 2002
C, or newer. Hmmmm.....
If you call and manage to get the right part, AND it works, please let everyone know.

p0170
 

and p0173 are maf fuel trim codes
http://www.autohausaz.com/search/mod...00016&year=All
has them for about $170 bosch units free shipping if proper cleaning per the diy on benzworld.org w210 diy section does not work.
ohlord:bow:

Hmmmm $226 for a Sieman's replacement vs. Bosch.
Bookmarked that one for a later date.

Hi,

I am new to this forum, but already found it very helpful… I bought my 2004 C240 4Matic (automatic) less than a month ago with about 36K miles on the clock… The car it self looked new and had a clean history… However, about a week ago, the Check Engine light came on. I had it serviced at a garage that specializes in MBs… As you probably guessed, it was the MAS… He replaced it, reset the codes and, upon my request, changed the oil (since there is no dip-stick and it was hard to tell what state the old oil was in). Since then, the car idles a little rough/shakes a little and hesitates when taking off from stop. Since yesterday, though, it stated dying on me when I first come to a stop --say on a traffic light. Restarting after that is no problem and the car will stay on (idling smoothly) even if I am still stopped. The problem seems to be more pronounced when the car is cold, but could still happen after a 10 minute drive in the morning or on my way home at the end of the day. I live on the east coast, so the temp here is fairly mild in May (mid 70s to mid 80s during the day.) The problem is a little worse if the AC is on (but I don’t think there is a direct relation there.)

To be fair, I noticed a bit of the rough idling/hesitation before the Check Engine light came on/car was serviced.

I have read this and another related thread, but they both seem to end abruptly. Has anyone come-up with a “definitive” cause or additional recommendation for this issue?

Any feedback is much appreciated, especially that my car is not under warranty and all repairs come out of my pocket! Thanks.

I got scammed by the same ebay guy!!!
 

ARRRRGGHH, thank goodness I found guys. I read the postings then went out to my 1999 C230K and pulled the wire for the MAF and Viola' no more hesitiation or jerking or loss of acceleration. I am still stalling a little bit which is annoying, it only happens when I pull to a complete stop after going fast, the car shudders then stalls. I am hoping a new MAF will cure all the problems. I just replaced my coils $130 from autohauz for both, it was a good deal, although now I don't think I needed to replace them. I replaced the fuel filter the other day, that really needed to be replaced it looked like it was going to rust out any second. So my question now is, how long can I drive around with my MAF pulled? Is it going to kill my car if it isn't plugged in? Or is something horrible going to happen?

The maf
 

when the car is under anything but full throttle with info from the o2 sensors regulates the air /fuel ratio.Unplugged or defective messes up your fuel ratio which left for a long enough period(and it does not take that long for unburned fuel to fry an o2 sensor)will cook your o2's
autohausaz.com
http://www.autohausaz.com/search/pro...0Mass%20Sensor
it is the real deal and takes about ten minutes to install and free shipping over $50.
:bow:ohlord
btw an obd2 scanner 94169 is only about 60 bucks at
http://www.harborfreight.com/cpi/cta...unction=Search
do you have the telltale p0170 and p0173 maf fuel trim codes?
Do you have a check engine light on?

Thank you, you are very right indeed! I just put in my order with Autohaus.az, $178 and change. I should have it in 3 or 4 days. I am not throwing any 400 codes so I figure right now, this second, I am ok with the 02 sensors, they are not toast yet. The whole ordeal is so annoying, I never had this problem with my 1988 190E, then again it doesn't have a MAF or OBDII or anything really, it's a what you see is what you get thing and it still runs pretty good.
The biggest job I have tackled so far was replacing the head on the 190, that was 13 hours of hell-but at least having said that there was nothing that ever stumped me or fooled me, at least not for long. The C230K challenges me on a continual basis.
The first MAF went bad from oil coating it. The real question is, where did the oil come from? It wasn't coming in from the oil separator, I checked that, it was dry. Possibly an inner cooling system/oil leak somewhere? I just don't know. What scares me is that it could happen again, I keep checking the MAF pipe looking for oil and I don't see any (anymore). Does the supercharger have it's own oil supply? Does anyone know how that works? I have the MB STAR cd and while it's good ($175 bucks good) I miss the old factory manuals made of paper, In my opinion they were just easier and better to use.

You know, in all that writing I didn't answer your questions. I already have a reader. On the first MAF I was throwing the p0170 codes. On the second MAF I started throwing P100 codes, specifically 100 and 110. 110 was the most recent. Yes the check engine light (CEL) always comes on.

By the way I love Harbor Freight, I have one right down the street from me in Brick NJ and it is just the best. I can buy an entire tool box with tools for the cost of one wrench at sears. They are so cheap they are almost disposable. While some of the stuff isn't the best quality, at least I don't cry when I break a tool anymore, oh and they replace all broken tools free no questions asked.

i also got scammed from ebay some guy claimed that the maf he was selling would fit in my 02 coupe kompressor and when i got it nothing happened my car still hessitated and the engine would shake.. etc.... my cars been in the shop for 2 weeks now and im fed up because mb doesnt know whats wrong and its rediculous.

I got MAF'ed by German star. The part number on the box was correct for the C240 but the actual numbers stamped on the maf matched those to the VW/Audi mafs. I called germanstar to let him know, he stated that you can have different part numbers but that the maf was for the car. I don't agree and am returning it. I just hope they honor the return.

My last post on the saga of the C230 was over a year ago and all ended well until last Friday. I had an issue with my maf and I cleaned it and it was all good. Now I have a p0450 issue which I didn't think was a big deal. Then all of the sudden the car wouldn't start, 4 -5 tries later and I got it started. Then the BAS light came on. Ok I figure the brakes need to be checked, then the car died in traffic this morning with no warning!! It took 4-5 tries to get it started but I got it going and made it to work. WTF is going on here? So at first I thought these were unrelated issues, but now after reading some of the threads I am starting to think they are related. My guess is that the K25 ABS relay is going-gone, and the K12 ignition brake relay is shot too. Other thoughts are that ESP module is bad and or a bad ABS sensor somewhere, not sure. Anyone care to guess?

My car when i first got it.. It shaked so bad at the stop light.. I would feel like **** if i had someone in the car and it started to do that.. Good thing it doesn't do that crap anymore..

I changed to all new wires and plugs and the issue went away..

0280217114


Bosch OEM
Air Mass Sensor
1 per car.

$424.00

$164.89
$173.57
SALE

Can anyone attest that this really is the right part, as it says its for 1999? It would be great to get the part for this cheap.