CEL and Low Idle
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Junior Member
Joined: Dec 2012
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2006 C280 4matic
CEL and Low Idle
I did some routine maintenance recently (I'm at 122,500 miles) and now I've got a CEL. I did an oil change 3 days ago with no issues. Today I replaced the original plugs with OEM Bosch. I changed the 3 in bank 1 first and started the car to make sure nothing was wrong. Everything's good so far. I completed bank 2 and then took a spin around the neighborhood, still with no issues. It sat for about 3 hours and then I drove about 15-20 miles still with no issue. I parked in a deck for about 45 minutes and when I cam back and started up I got the CEL. I noticed the RPMs were low while in P and when stopped in D, around 550 or so, but there isn't any roughness or vibrations. Other than this the car drives fine. I tried getting the codes read at an Autozone on the way home but the scanner kept coming back with 'NO LINK'. I know it could be a number of things with no specific codes but I guess I wanted some scenarios. I'll try another source or more than likely pick up a scanner tomorrow.
I had my B service a year ago from a local indy shop but since I had the air box off I decided to take a look at the filters and see/learn more about my car. I found dirt, bugs, a couple moths, etc trapped in the filters and a little bit on the screen to the MAF. I cleaned up what I could and reassembled everything.
That's a pretty complete run down of everything that happened before this CEL, which happens to be the first time I've seen this on my dash. I was thinking maybe some of the loose dirt and such could be affecting the MAF so I picked up some cleaner while at Autozone.
Any suggestions?
I had my B service a year ago from a local indy shop but since I had the air box off I decided to take a look at the filters and see/learn more about my car. I found dirt, bugs, a couple moths, etc trapped in the filters and a little bit on the screen to the MAF. I cleaned up what I could and reassembled everything.
That's a pretty complete run down of everything that happened before this CEL, which happens to be the first time I've seen this on my dash. I was thinking maybe some of the loose dirt and such could be affecting the MAF so I picked up some cleaner while at Autozone.
Any suggestions?
Last edited by TheOnlyBaleki; Jan 18, 2013 at 09:50 PM.
Thread Starter
Junior Member
Joined: Dec 2012
Posts: 24
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2006 C280 4matic
I had a similar issue with my other car not connecting to a reader and it ended up being a missing fuse so I checked that first on MB. Nothing was missing or blown. After doing some research, and if I read everything correctly, it turns out that the code reader from Autozone didn't connect because its not CAN compliant.
Like I said, I'd like to pick a reader up tomorrow, preferably an Innova. Does anyone know if they're sold in any brick and mortar?
Like I said, I'd like to pick a reader up tomorrow, preferably an Innova. Does anyone know if they're sold in any brick and mortar?
MBWorld Fanatic!
Joined: Feb 2009
Posts: 5,054
Likes: 11
From: fort worth, tx
06 C230 SS 6spd
just buy a cheap reader from Harbor freight that costs like 50 dollars, just make sure it reads OBDII and CANBUS or just go to any parts store and have it done for free.
Thread Starter
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2006 C280 4matic
I just read my codes and they were P2190 and P2188 (System too rich at idle bank 1 & 2). I'm ordering new Mann air filters but in the meantime I will double check that I reinstalled the air box correctly. Should I attempt to clean the MAF, and if so, should I do it now or wait until I put in the new filters?
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2006 C280 4matic
Just a quick update:
Had a chance to look at the air box after reading about having it seat completely over the MAF. It, in fact, was about 1/2" and leaving a sizeable gap.
Before:
After:
I found that seating the airbox from rear to front worked best. Align the rear and pound it down, the rest should follow. Reconnect tubes and hoses. The codes haven't cleared yet, but I'm fairly confident this was the issue.
Had a chance to look at the air box after reading about having it seat completely over the MAF. It, in fact, was about 1/2" and leaving a sizeable gap.
Before:
After:
I found that seating the airbox from rear to front worked best. Align the rear and pound it down, the rest should follow. Reconnect tubes and hoses. The codes haven't cleared yet, but I'm fairly confident this was the issue.
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Joined: Jan 2005
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From: Orange County
2005 C Wagon (No snickering please!)
The screen over the MAF (Mass Airflow Sensor) should be as clean as the day it was born. I think you found your problem with the leak in the intake past the filter. You do need to clean the MAF sensor and the intake to remove the atmospheric dirt. Use the CRC cleaner per the directions on the can. It will do the job.
Get the Mann+Hummel filters installed and make sure they seal well. Reset the codes and MIL (Malfunction Indicator Light) and enjoy the rest of Sunday.
Get the Mann+Hummel filters installed and make sure they seal well. Reset the codes and MIL (Malfunction Indicator Light) and enjoy the rest of Sunday.
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2006 C280 4matic
I've got the Mann filters installed and the MAF off and cleaned. I want to go ahead and clean the throttle body since everything is apart. Does this elbow pipe just twist off? It rotated a little but I didn't want to yank on it and break something. Thanks for all the help guys.
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Thread Starter
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2006 C280 4matic
Reassembled everything and the idle has smoothed out. However, I now noticed that the "After Start" display showed my MPGs dropping to below 11 even at idle. I've been averaging in the 20s. CEL is still on so I'll recheck them.
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