Vabene7

Driving in NJ yesterday and using the shifter to go from 2nd to 3rd and at 5000 rpm the car cuts out - no throttle and the ESP letters come up on my display screen where my speed would normally be.
I get to the side of the road and shut the car off. When I try to restart the car, it starts fine, no more ESP in the display but now the check engine light is on.
I had a flatbed pick it up and brought to the dealer.
Pit in my stomach......I am out of warranty.

I wonder what the hell happened.....
I will know more tomorrow when it gets diagnosed.

Arya

that sucks. let us know what it is.

Stiggs

Damn. Stories like this make me nervous that I have no more warranty left. How many miles on your car?

Vabene7

I have 58k miles on the car.

I found out it is the MAF sensor. The dealer wanted $775 to do the repair/replacement.
I told them "thanks for the Star Diagnostic" and I picked it up today for a DIY tomorrow.
MB wanted $450 for the part, I got it at MBpartswarehouse for $250 including overnight shipping - arriving tomorrow.

trikoid

Nice work - my favorite kind of problem: one where you know the solution.

Let us know whether it fixed it.

archony

That's great to do the work yourself: you get the satisfaction of doing the work and it costs a lot less.

Vabene7

Well, I just gone done replacing the Mass Air Sensor.... Runs great again.
It was an easy fix. Took me 20 minutes and rather than replacing the internal sensor (which you need a special torx bit with a hole in the center) I replaced the entire mass air. Got it from www.mbpartswarehouse.com for $208.25 plus overnight shipping (dealer wanted $475 plus tax for the part alone). I was under the hood for 20 minutes and the only tool I used was a flat-head screw driver to pry apart the circular clip that holds the mass air housing in place.

I am happy I saved the $$$ by doing it myself.
I will have to wait and see if the check engine light goes off by itself. I was told it should reset and turn off after 40 minutes of drive time.

Whew......crisis averted.

JuicedMB

I'm glad that you were able to get your car on the road. I think it is great to hear when others are able to fix problems and not get taken in the shorts by the Dealer......

trikoid

40 minutes of drive time? What'd you do, change the sensor, and then run in and tell us online people? Go, man, go! Drive! Drive! Make that light turn off!

unitfreebie

Glad you're back on the road... usually the CEL will throw an error code P0170 meaning a bad fuel trim if the MAS is bad. Mine threw a check light at 68,000 miles but kept running... and got a new one from FleaBay for $165; cured the problem.

Your MAS must have had a really bad failure to shut down the engine... usually the MAS wire gets coated with debris/chemical/crap/etc and can be cleaned with a can of MAS spray (not anything else, or the wire will be ruined).

I was able to reset the CEL error code with a DTC reader from Kragen and drive around a few hundred miles before it would reappear. So I just replaced the MAS.

One source of MAS failure causing the CEL to light is a poor O-ring seal at the front of the MAS housing allowing dirty air to pass onto the wire and coating it.

Another source of dirty air is the K&N filter which does not filter down to 10 microns like the Mercedes stock filter, thus allowing fine dust/debris particles to coat the wire sensor and causing the MAS to fail. So the stock filter is the best to use... use the K&N only for show and go... not daily usage.

K&N also states that when cleaning and re-oiling the filter use only the specified amount of oil, as excess oil will be blown off the filter and coat the MAS wire sensor causing a failure.

Have a nice day...

Vabene7

The check engine light finally went off after I drove it around for a while last night.
Back to normal.

unitfreebie

Glad to hear everything is back to normal....

Say, how much real HP gain is that STAGE 2 ECU giving you??? What octane gas is it mapped to?

AND does it affect the smog emission test?

Vabene7

Oliver from speedtuningUSA says 20-25 HP. I have yet to dyno.
The car definitely ran stronger after the ECU was redone.
I had it mapped to 93 octane because we can get that in NJ.
It also does not affect any emissions test.

unitfreebie

20-23 HP gain is a lot... you can feel that ... but then it's using 93 octane which I don't have around here or is easy to get.

There was another chip I looked at that gave +10 HP gain using the 91 octane fuel.

Thanks...