crispychris9

So these codes are constantly turning my check engine light on... Any help is greatly appreciated

chazman

I really had some good lucks with cleaning the MAF sensor when I had such CEL codes - using CRC MAF sensor cleaner.
Search and learn how to do that.
If cleaning doesn't work, you may need a new sensor.

turbonos7

I'm guessing you have a V6 with dual MAFs? First question, are you running K&N air filters? If you are you might want to try and clean the sensors like mentioned above, and change back to OEM air filters and go from there. Hope that helps.

crispychris9

I'm not really sure if it has 2 MAFs but I know it has the one in the main intake port towards the rear of the engine. And yes I am running dual K&N drop in filters

crispychris9

Is it the oil messing up the sensors?

chazman

Theoretically oil from the K&N filter can cotaminate the MAF sensor.
I think there must be excessive amount of oil on the filter though. If you applied correct amount of oil or if you just drop in the filters as new from the box, it would not have contaminated the sensor.

If you pull out the sensor, often times, with good lighting, you can tell whether the sensor needs cleaning or not (in my case it was quite obvious).

To find out whether you have single (my bet) or dual MAF sensors on your C280, call a MB dealer or even a local auto parts store and ask.

turbonos7

You might just have one from the sounds of what you are saying since it is "centralized". I got confused for a second with my Land Rover LR4 which has 2. Anyways, I had an LR3 before and I put in a K&N and shortly after started getting weird CEL events, hesitation, and it even shut off on me a couple of times. At the time it was still under warranty so I took it in, they called me back and told me that they'd recommend taking the K&N off and cleaning the MAF and putting a new OEM filter in. I agreed as this was my wife's vehicle and did not want to hassle with it and I never had a problem after that ever again.

Then I purchased my '05 C230 SS and got compulsive and bought a K&N filter for that one too. I wiped it down before I put it in since I learned a little from my previous experience and as long as it was in I did not have or get a problem BUT, I was used to getting 31 mpg during my 60 mile one way commute to work everyday (I work 2 miles from the highway so this helps) and since I put the K&N filter in the best I got was 28.5 on the same route, same general temps, same general traffic, same gas... you get the point right? I slapped the OEM back in and 31's came back. Honestly, I didn't feel a change in performance. Just my 2 cents! Good luck with your issue. Hope we have been of some help.

crispychris9

So it's probably best you think to return to the OEM filters..?

turbonos7

I would, I mean I did! There's a really good chance that your MAF is dirty so cleaning it and putting oem filters back in can only help. At least until you get the problem figured out. If you do this and the issues don't return, well then you have your "empirical evidence"

turbonos7

Groups of CEL codes to me are like those reading sections of the SAT. You read them all (whatever you can understand) and try to get the main idea out of it of the theme. Instead of a single code trying to tell you which exact component is bad so that you can replace it, it is actually more like "what component do all these have in common, or system per say" well you got mixture rich, mixture lean, can't retard anymore to try and stop detonation from mixture being too lean, and I forget what the other one was. Looking at that I'd say "well only two major components have a big impact on the calculation of air/fuel mixture, those are O2 sensors and the MAF, well no O2 sensor codes AND I do have K&Ns which have been known to in some cases cause MAF problems.... well it's kinda obvious at that point.... for me

turbonos7

Also, even though I think we have this figured out, can you tell us the mileage of the car, when you put in the K&Ns and when did the codes start showing up? You know... some more backround info please? thanks!

crispychris9

The mileage is about 120k, I put the k&n about when my mother got it which was 40k, and codes started coming up around maybe 110k or so give or take

chazman

Chris,


How abou this:

What kind of MPG have you been getting, if possible before and after K&N?

Was there a noticeable MPG drop since the CheckEngineLight (CEL) coming on? If so, what is it now?

crispychris9

Honestly I don't know because it is my mom's car and she fills it and she doesn't really keep track of the mpg so yeah

turbonos7

Yeah, that's kinda what I was trying to get to since I did that on my own car but being that the K&N was put in so long ago with no problems I wonder now if he "serviced" the filter and put too much oil on or something. Or maybe it has been passing dirt long enough and it is finally time to clean the MAF and go for another 80k "clean" miles?

chazman

Chris
Have the K&N filters ever been serviced/reoiled since they were installed new?
Has th air box (that encloses the air filters) ever been taken off/reinstalled for any kind of service since the K&N filter installation?

tommy

I wouldn't be so quick to blame the K&Ns. It could be a number of things.

Moviela

Now that you own the scanner, you are free to remove the plastic film over the screen.

It could be a number of things like Tommy says, but the MAF sensor is the easiest to clean.

I have no knock against K&N but they sure oil up the intake. They also have trouble sealing properly in the Mann+Hummel designed air filter housing. I have seen more than one car with dirty air entering the intake around the filter edges.

Stick your finger in the MAF sensor holder and wipe the inner wall. If it is other than kitchen counter clean with oil or dirt, replace the oily filters with the specified Mann+Hummel filters. Clean the air cleaner parts with warm soapy water and dry well.

Clean the MAF sensor following the direction on the CRC can to the letter. Don't touch the sensor with anything. Any surface contamination will spoil the readings

crispychris9

Oky so I cleaned it with the spray and cleared the codes and the engine light came back on.. I service the filters every time I change the oil so yes they have been recently serviced

turbonos7

Every single code came back? Did you use the CRC MAF cleaner or a substitute? Did you follow the directions on the can to the "T"?

chazman

Makes sense.

BenzKompressor

The cam adjustment codes were what concerned me most... I cured my funky check engine issue by simply replacing the battery and clearing ALL codes in every module in the car (including the CAN bus). Then from there I was able to tell which of my errors were valid. Turns out I only needed an upstream O2 sensor.

Check all of your vacuum hoses, too!

But all of my issues stemmed from a bad battery!!!

turbonos7

I would replace the MAF next but taking what BenzKompressor just said into account you want to go the cheapest route first so find a way to test the battery SAFELY, and if that checks out then you can rule that out. Vacuum leaks are a good possibility also.

BenzKompressor

These cars are EXTREMELY sensitive to "low" battery voltage. And I put low in quotes because what was conventionally considered low battery voltage is way past what will make these cars start to act up!

Mine starts to freak out at around 12.1 volts!!! This causes the CAN Bus to transmit bad data between the modules and makes the modules themselves act up.
One example is the Rear SAM started throwing codes of burn out tail lights, reverse lights, etc. The bulbs were in fact good.

Another is the sunroof wouldn't "one touch" close.

My major example is P0120 "throttle control circuit". The engine would start and bounce from 1500-1800 RPM very quickly and I would have NO throttle control.
The condition got worse as the battery got worse (naturally as the winter got colder!)



Once the battery was replaced the symptoms didn't go away on their own... I had to get the Mercedes specialized diagnostic system (DAS with Compact4 multiplexer) and read and erase faults/events in EVERY module before the symptoms went away. That was 3 months ago, no related issues or codes have returned! So your over the counter OBDII reader is NOT sufficient to cure the issue I had.
The system was like $300 shipped. It is a chinese hacked version, but they are extremely helpful in supporting any issues you have with the system. Just a word of warning: You need to be somewhat computer savvy to setup and use this system!