Bank 1 & bank 2 too rich
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Joined: Aug 2024
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From: Brooklyn park , MD
Mercedes-benz C300 2011 4matic sports
Bank 1 & bank 2 too rich
I just solved this issue 2 weeks ago and it came back. But the thing is now , is that I literally feel nothing wrong with my car . It’s driving great , there is zero noise , no vibrations . Cleaned my MAF sensor 2 weeks ago. I’m gonna check the air filters after this snow storm . Maybe there’s my issue . But I want to hear another opinion .
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Joined: Feb 2008
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From: Rivers, Manitoba, Canada
2009 Mercedes C63 AMG, 2013 Mercedes C350 4Matic Coupe. 2012 GLK 350 4Matic
I have the same issue 2012 GLK350 4Matic
I’ve run all scans, had this off and on for quite a while.
Ive scanned everything, found nothing. found an article that points to the MAF sensor as the most likely culprit.
is the a way to test this sensor?
I just solved this issue 2 weeks ago and it came back. But the thing is now , is that I literally feel nothing wrong with my car . It’s driving great , there is zero noise , no vibrations . Cleaned my MAF sensor 2 weeks ago. I’m gonna check the air filters after this snow storm . Maybe there’s my issue . But I want to hear another opinion .[/QUOTE]
Ive scanned everything, found nothing. found an article that points to the MAF sensor as the most likely culprit.
is the a way to test this sensor?
I just solved this issue 2 weeks ago and it came back. But the thing is now , is that I literally feel nothing wrong with my car . It’s driving great , there is zero noise , no vibrations . Cleaned my MAF sensor 2 weeks ago. I’m gonna check the air filters after this snow storm . Maybe there’s my issue . But I want to hear another opinion .[/QUOTE]
Out Of Control!!
Joined: Apr 2019
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From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
B1/B2 : Rich AF...
Both banks too rich... (bad for cats!)
can you read your fuel trims?
Have you cleared faults from your ECU after recent MAF service... do it.
can you read your fuel trims?
Have you cleared faults from your ECU after recent MAF service... do it.
Last edited by CaliBenzDriver; Mar 4, 2026 at 06:48 PM.
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From: Brooklyn park , MD
Mercedes-benz C300 2011 4matic sports
was diagnosing the car for being rich and this happens . Looks like my belt kinda burned the groves . This is a whole new problem
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From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
new priority shuffle
Ultimately at least replace belt kit: tensioner + idlers + serp. (+ accessories).
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From: Brooklyn park , MD
Mercedes-benz C300 2011 4matic sports
Out Of Control!!
Joined: Apr 2019
Posts: 12,003
Likes: 6,827
From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
What is $1000 ?
This job starts with a belt kit ~$150 + TBD. failed accessories.
Last edited by CaliBenzDriver; Mar 5, 2026 at 09:04 AM.
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From: Brooklyn park , MD
Mercedes-benz C300 2011 4matic sports
it’s just replacing a belt and some pulleys , would I need to do something else other than replacing belt & pulleys? You telling me to take it to a shop?
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Thread Starter
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From: Brooklyn park , MD
Mercedes-benz C300 2011 4matic sports
also back to this . Before my belt gave out , I was scanning ECU for codes and now it’s just saying Bank 2 is rich and bank 1 is okay . I have cleared the code when I finished the service . When I look at my fuel trims what am I suppose to be on a lookout for . Say for example , my MAF sensor is going bad , what kind of data would I look for? Or say my O2 sensor was going bad , what data stream would diagnose that? Sorry I’m still new to diagnosing , I don’t know what data is for what.
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From: Brooklyn park , MD
Mercedes-benz C300 2011 4matic sports
Also this is kind of a stretch but I have heard rain and snow would be the cause of this . How accurate is that? I really don’t believe it.
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From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
also back to this . Before my belt gave out , I was scanning ECU for codes and now it’s just saying Bank 2 is rich and bank 1 is okay . I have cleared the code when I finished the service . When I look at my fuel trims what am I suppose to be on a lookout for . Say for example , my MAF sensor is going bad , what kind of data would I look for? Or say my O2 sensor was going bad , what data stream would diagnose that? Sorry I’m still new to diagnosing , I don’t know what data is for what.
- low fuel pressure
- old Lambda upstream sensors
- Overgapped spark plugs
- dirty MAF sensor
- oily MAP sensor
Out Of Control!!
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From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
Many ppl know that RAIN LEAKS can royally mess up MB. I bet salty snow can pack a treat too...
Pop the hood open,
use your scanner,
investigate reality...
Dealer are here to help with trained technician who can diagnose your issues often for a small fee.
Out Of Control!!
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From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
wobbly pulley bearings
Someone needs to assess the accessories to make sure only the tensioner caused the slippery belt failure.
The service of serpentine accessories is really not time consuming nor too expensive if nothing else
Last edited by CaliBenzDriver; Mar 5, 2026 at 05:49 PM.
Thread Starter
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Joined: Aug 2024
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From: Brooklyn park , MD
Mercedes-benz C300 2011 4matic sports
I have a launch Creader elite V2.0 I kind of don’t know how to look for specific data . Like MAF OR MAP or low fuel pressure data . Overgapped spark plugs can cause my engine to run rich?? I figured that’ll be a misfire ? Sorry for asking a lot of questions I really want to get to the bottom of my engine running rich
Thread Starter
Member
Joined: Aug 2024
Posts: 85
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From: Brooklyn park , MD
Mercedes-benz C300 2011 4matic sports
I’ve run all scans, had this off and on for quite a while.
Ive scanned everything, found nothing. found an article that points to the MAF sensor as the most likely culprit.
is the a way to test this sensor?
I just solved this issue 2 weeks ago and it came back. But the thing is now , is that I literally feel nothing wrong with my car . It’s driving great , there is zero noise , no vibrations . Cleaned my MAF sensor 2 weeks ago. I’m gonna check the air filters after this snow storm . Maybe there’s my issue . But I want to hear another opinion .
Ive scanned everything, found nothing. found an article that points to the MAF sensor as the most likely culprit.
is the a way to test this sensor?
I just solved this issue 2 weeks ago and it came back. But the thing is now , is that I literally feel nothing wrong with my car . It’s driving great , there is zero noise , no vibrations . Cleaned my MAF sensor 2 weeks ago. I’m gonna check the air filters after this snow storm . Maybe there’s my issue . But I want to hear another opinion .
Sorry for this being late!
there is ways to test the sensor depending on what scanner device you have . Have you solved your issue ?
Thread Starter
Member
Joined: Aug 2024
Posts: 85
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From: Brooklyn park , MD
Mercedes-benz C300 2011 4matic sports
That's not impossible unless you live in the Bahamas. Ppl give you handy tips to help you check this out.
Many ppl know that RAIN LEAKS can royally mess up MB. I bet salty snow can pack a treat too...
Pop the hood open,
use your scanner,
investigate reality...
Dealer are here to help with trained technician who can diagnose your issues often for a small fee.
Many ppl know that RAIN LEAKS can royally mess up MB. I bet salty snow can pack a treat too...
Pop the hood open,
use your scanner,
investigate reality...
Dealer are here to help with trained technician who can diagnose your issues often for a small fee.
I don’t want to just ignore this and wait till it progresses lol it just confuses me a bit .
Out Of Control!!
Joined: Apr 2019
Posts: 12,003
Likes: 6,827
From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
Something that confuses me is that it’s running perfect and idling like normal . Maybe when i enter the freeway and try to accelerate there’s a bit of a small jump, but it’s really not that noticeable unless you focus on it .
But that rarely occurs .
I don’t want to just ignore this and wait till it progresses lol it just confuses me a bit.
But that rarely occurs .
I don’t want to just ignore this and wait till it progresses lol it just confuses me a bit.
- Engine (..., pigtails, good oil, ...)
- Transmission ATF
- Suspensions (SB links, arms, BJ, ...)
- Tires + Brakes services
- Leaks: oil, coolant...
- Batteries (trickle charge,...)
Your MB likes any new genuine parts & care you give it.
"Bk1+2 too rich" brings ignition up to the head of the list.
opportunistic free loaders soaking sun 👏
Last edited by CaliBenzDriver; Mar 10, 2026 at 06:47 PM.
