Have a 2000 c230 kompressor and a few days ago the check engine light came on. Autozone's OBDII reader shows a P0170 Fuel Trim Malfunction (Bank 1) code. I've read that this could be caused by a faulty Mass airflow Sensor but there's more....I also noticed that when I try to accelerate quickly, the car "stumbles" badly and almost like it is about to stall. Acceleration is real gradual. Would a bad mass airflow sensor cause this type of problem also or do I have a bigger issue (like the turbo has died)?

 

air mass sensor problem.
replace it by warrenty if u still have them.

by the way, u dont have a turbo, right?

 

I do have a turbo. Car is 5 years old and has 70K miles so no warranty.

 

sorry for the tatkins

just need to ask DEMON if he is planning on attending
the 2nd Annual San Diego MB / AMG Meet on July 9th ???? Please click on LINK to get more info & sign up. Thanks.

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ok, back to Turbo's and MAF Sensors....

 

Mass Air Sensor - if you are handy - buy it and install it yourself and save the $'s from having the $tealership do it.

 

More than likely the MAS is starting to go out on you. Also make sure your plugs are still good, and check your airfilters while you're at it.

BTW, you dont have a turbo, you have a supercharger or "kompressor."

 

Thanks for the information. I'm a newbie to the benz family. Had the car for about a year. Funny you mention the plugs because today it started idling very rough. Shakes like a "truck" while sitting at the redlights. Don't know if this is a further progression of the MAF going bad or an indication that the plugs need to be changed also. So I guess I'll change both the MAF and the plugs.

 

if it's "fishing" for idle, then it's probably MAF.
by "fishing" i mean RPMs go up and then come back down and then go up again.
getting the MAF online and putting it on yourself is not a tough job to do. one can probably find MAF online for 200 bucks or something.

 

Thanks for the info. Just called the dealer (what was I smoking???) and they have it for around $450.00. I'm assuming that the MAF and an Air Mass Meter is the same thing because that the only name I've been able to find online. If that's not correct...somebody please stop me!!!

 

Shop around......that is WAY HIGH...........

 

Shoot me an email. I can get you one for probably about half the price. New/OEM/Bosch. Also, it's pretty easy to install.

 

search this forum a few of the members including myself just went thru MAF replacements of our own and some of the sources were discussed here. i've got mine (brand new bosch) for 203 including shipping from an e-bay seller. he seems to be OK, shipped quicky. item was really new in original package, etc. use at your own risk though

 

Thanks found it at a much lower cost. While I'm waiting on the unit to get here, I went ahead and changed out the air filter. When I took the old one out, I've never seen one so dirty. Replaced it with a new one and after a day or so the CEL went out......maybe it will come back later but the filter definately needed to be swapped out.

 

i ran into a very similar problem like yours. here is the order of events for me,
without replacing any parts.. my idle got pretty rough while in gear when im at a stop. one day i decided to change my air filter because it has been a while, after i replaced it my CEL came on and it made me regret changing the air filter. i got the same codes as you from the odbII. although now the CEL comes on my rough idle has definitely lessened dramatically and my gas mileage is great (better then before).. i have a 1999 C280 and get 370 miles on a full tank compared to 340'ish prior to air filtler change.

did you change your plugs, if so did the rough idle stop completely?

 

No haven't changed the plugs yet but the CEL has stayed off since I replaced the air filter. Got the MAS today and installed it this evening. Car is running great!!! I plan to change the plugs out this weekend. Thanks.

 

I Got the dreaded Check engine light after installing K&N Filters on my 08 E350. Checked the code and it was a Fuel trim malfunction. I called K&N and got the Best customer Service. Anyway, the Techy said to get Mass Flow sensor cleaner and clean the MFS before taking it to the dealer. The oil from the filter and the pre existing dirt on sensor wire could be the issue. I bought the MFS cleaner at Autozone 7 bucks. Removed the MFS from car, piece of cake I might add (YOU TUBE) sprayed this stuff on the sensor wires and re installed. reset code. drove car all day and so far no check engine light.