P0170 Air Mass Meter Question
 

Hello, My wife's 1997 C280 MIL has come on with code P0170 only. The car has 150K miles on it and we are the original owners. I went for a ride and logged the long term fuel trim with the MIL on 1.32% and off 1.32% A few days later the MIL came on again. I have searched this forum as well as the internet for a troubleshooting procedure specifically for the AMM. What is the common mode of failure for the AMM, is it a wide open condition or a drift outside of the normal operating range? There should be an acceptable range of resistance values or frequencies at a given RPM/Load/Temp/Humidity for this device. Does anyone have the pinout descrition for the connector? In a second note I have seen the AMM for this car range in price from $169(Ebay, manufactured in the same plant as the MB but not labeled MB) to $474 (dealer, definetly labeled MB), has anyone bought one from ebay with good results? Thanks for your help!

I get mine from Bosch for $77.00 wholesale for the insert only, thats all you need.

The dealership sells you the housing and the insert.

they really stick it to you don't they.

Look into the Bosch mass airflow inserts, you will be a happy camper.

German Auto parts carries them.

I'm sure many people would like more info on this insert. It sounds like a great way to save some money. Could you give more details? Bosch part number , a link to the website, maybe a photo?
Thanks, Dan

man, I knew you would ask that.

I don't have the part # handy.

I just give the cars vin# and part # off the air mass when i need, one, I call GAP and they deliver it to me.

I'm sure you can find them on Bosch's website unless it is a wholesale item only.
I just started getting them last month when my buddy told me they were available.

You do need a tamper proof torx socket to get the insert out, and they give you phillips screws to go back in with.

I can get more info tomorrow for y'all.

Update
 

I emailed george at GAP and he told me my part "0280218080 is no longer in our inventory" . He did quote me the full replacement housing "000-094-10-48, air mass meter" for approximately $280. I saw a sensor replacement on Ebay but it is only for a 1998 C280 and up. I have since taken the sensor out of the housing and cleaned it with contact cleaner, but it wasn't that dirty (if at all). I cleared the "CEL" and now am waiting to see how long before it comes back on. I will hook up the laptop again this weekend to see if the long term fuel trim is coming down. Thanks for your input(s).

When you get that "insert" for $70. You are buying a VW part that you could get for less than $45. at VW dealer...what Bosch says that you are doing id damaging the fuel & exhaust system as that sensor isn't at all correct for a MERCEDES! So ...what do you do? Install INCORRECT parts that can & will cause problems?..or spend more $$$ & install the correct part..

Bosch has instructed THAT vendor to stop selling that part for MB's..but that almighty buck sure looks good..

Dear ccloser:

Do NOT buy that $169 MAF from Ebay!!! They are cheap because they use the HOT WIRE design whose voltage signals can never match the pre-programmed characteristic curve calibrations of an OEM Bosch MAF that uses the hot-film design. Your OBDII CEL will always come up if you use such cheap MAF. Been there, done that.

Spend the money to buy a genuine Bosch hot-film MAF for your car's specific model. It's not worth your money and time to buy the cheap one.

Eric

That is strange.

then why does gap not tell the buyer the info you just shared?

Need to do some diggin on this one.

What vendor is that?

Every one I bought from gap worked fine, I have to dig up old receipts for part #s.

So you are saying that gap is selling parts for mercedes that do not apply to that vehicle...Hmmm.

I view installing incorrect parts as unethical!

GAP in Atlanta does NOT or ever has sold any air mass inserts they sell only the complete sensor designed for the correct application!

You never got an insert from anyone but The Bri.... Company!

You are right, I'll clean out my crack pipe and remember next time who I got my parts from, sorry.

Too many vendors to keep track of.

I'm not one of those guys that can't admit when I'm wrong, thanks for correcting me.

A little embarrassment never hurts anyone from time to time.

I'm retarded. (Tommy Boy).

Final Update
 

The MIL came on again about 3 weeks ago and I broke down and bought the Air Mass Meter online for appx $310 on line (thebenzbin.com). After installation (I also replace air filter while I was in there) the long term fuel trim immediately dropped to 128% during a 3 mile drive around the block. It has been 3 weeks and about 500 miles and all is well. I replaced spark plugs and fuel filter this past weekend and it seems to be running perfectly. Thanks for everyones help.