id64

I don't think that it can reset itself since those codes were written permanently.

gonzales25

Thanks I will!!

DAGREEKNYC

some cars just need to be driven for a while IMO . my truck had check engine light on it after long tubes and new exhaust . we tried resetting the cpu and it came back after a day . after driving it for a few months then we reset and never came back .

LB63

Just did it, no CEL I could feel the difference too, it pulls more in the top end.

id64

What exactly you did?

DELETE only or

DELETE and K&N?

I am not getting CEL with delete only

Autoscope

Nice work guys! Is there still a screen infront of the MAF?

gonzales25

I thought the same thing, I was just worried about possible damage to the engine by running it lean. I know these mercedes engines are pretty picky from what I can see.

Thanks

DAGREEKNYC

from what i have heard running a car too lean has less risk of blowing a motor . This is coming from Ford guys so who knows lol . Also i reset the cpu today and once i got over 120 the light kicked back on . i think its because i have the air baffles opened up and im just getting too much air flow because under normal driving it does not kick the cel on .


codes coming up are fuel trim error bank 1 and bank 2 . meaning both intake boxes

GHAZAN

I think it's the opposite....leaner means higher pressure/heat generated in the combustion chamber and a greater chance of blowing the motor. Correct me if im wrong

id64

I've got my ODB2 tool yesterday and decided to try it again. First couple of hours - OK. Then as soon as I thought that I may be did something wrong first time - CEL. Same error codes about running lean, I can post full error report later. Cleared error, install stock paper filter with no charcoal - NO CEL.

id64

On

Diagnostic Trouble Codes

Generic Powertrain

P0171 System Too Lean (Bank 1)

P0174 System Too Lean (Bank 2)

Freeze Frame for DTC 171

Fuel System Status Bank One
Closed Loop

Fuel System Status Bank Two
Closed Loop


Calculated Load
19
%
Coolant Temperature
181
F

Short Term Fuel Trim Bank One
9.36
%
Long Term Fuel Trim Bank One
-11.70
%

Short Term Fuel Trim Bank Two
8.58
%
Long Term Fuel Trim Bank Two
-11.70
%

Fuel Pressure
51.76
psig
Intake Manifold Absolute Pressure
8.9
in.hg

Engine RPM
610
r/min
Vehicle Speed
0
MPH

Ignition Timing Advance for #1
12.0
deg
Intake Air Temperature
104
F

Air Flow Rate From Mass Air Flow Sensor
0.61
lb/min
Absolute Throttle Position
12
%

Enhanced Powertrain CAN

0745 Self-Adaptation Of Mixture Formation For Right Bank Of Cylinders Is At Liwith Value (At Idle Speed).Self-Adaptation Of Mixture Formation For Enrichment At Idle For The Right Cylinder Bank Is Above The Permissible Limit. (P0171)

2091 SummenError Der Selbstanpassung, Rechte Cylinderreihe

0749 Self-Adaptation Of Mixture Formation For Enrichment At Idle For The Left Cylinder Bank Is Above The Permissible Limit. (P0174)

2095 SummenError Der Selbstanpassung, Linke Cylinderreihe

GermanCars

Any luck with your fuel trim faults.
By the look of the freeze frame data, the computer is correcting (taking fuel away) more in the upper ranges than adding at idle. We have found that a fuel trim code set at idle may be caused by a fault at part/full load. The computer can adjust the fuel trim in only one direction. If the computer sees an over rich condition at part load, it will move the fuel curve lean through out the whole range. That can cause the lean condition at idle. The real question is why is the mixture so rich at part-full load. Is the the mass air sensor seeing a large increase in air flow with the carbon filters removed and K&N's installed?

NCE500

I removed my charcoal filters, replaced the (dirty) air filters with new OEM Mann units, and did the ECU reset.

My car runs noticably better across the RPM range, and pulls very hard to redline. No CEL or drivability issues at all.

This simple mod really woke up my car, for all of $26 for new air filters and about 15 minutes of time.

While I have not tried them, I think K&N may be overkill; clean stock filters appear to flow more than enough air for a stock engine.

GermanCars

I don't care much for K&Ns. I once had one in a 535I. The outer rubber support melted and left the engine unprotected. Thats a bad thing down here. Florida is a big sand pile. I might use one in a race car but not on the street.

LB63

For those with lean A/F, just make sure you closed the airbox correctly. When I changed the stock filters I thought I closed the airbox tight but then I noticed pinging under load when I took it out for a drive.

I opened the hood and saw nothing wrong. The boxes looked fully closed and nothing was being squeezed. However, when I removed the lid on the airbox I saw that the part of the rubber/foam on the edge of the filter was pinched by the air box and the air box cover.

After seating it correctly the pinging went away. However, I never had a CEL with the pinging

RNS-11Z

were do i get the tool to remove the covers for the filters? do mercedes sell them?

Sincity

I installed the K&Ns and removed the charcoals when the car was at about 300 miles. So far no CEL.

id64

I think that I've checked everything and I did it couple of times.

julian14

Hi guys, i did remove the charcoal filter and drove around for 4-5 days with old air filter NO ECL then the K&N filter arrive and replace the old arif ilter and drove for about 50 miles and ECL came on. What do i do now?? replace the K%N with OEm filter or put back charcoal back in???

LB63

The fact that the CEL went on shortly after you put on the K&Ns shows that the K&N is the cause.

Replace the K&N with new stock filters and then reset the ECU. The CEL should go away after this.

julian14

Thanks LB63, how due I reset the ECU do i have to take it back to mercedes dealer??, thank again

LB63

The instructions are in this thread https://mbworld.org/forums/w211-amg/...set-works.html

The Search button is your friend

princemarko

Take the KN's out. Put back your stock filters minus the charcoal ones. The MAF is faulting because of the K&N's. Its happened to me a bunch of times in different cars. Your engine light will go away after a couple of days of driving.

urquattrogus

Do we know if the charcoal filter is only fitted to US cars due to emissions regulations?

what about in the UK, this was certainly true with M5's (no charcoal filter in UK and or other markets)

citylightva

They actually have an entirely different upper airbox in the Euro models. Flows a lot more air and doesn't have the plastic lattice under the charcoal's, but they don't actually have charcoals...