I have a 2004 W211 E320 and few weeks ago my engine started misfiring. I changed my spark plugs i know its not ignition coils they've been replaced too. My only guess is the cats. Missfire occurs when i go 3500rpms and up the engine starts making weird noises and eventually shuts off after like 2 mins. I changed my primary O2 sensors too. Any help would be appreciated. The car starts shaking too and the engine won't accept any throttle.

Comments

Profile picture for user MBFanatic

It could be the cats but first I would check the fault codes. Have you done that yet? 

What are the codes? 

 

Bad cats would cause the symptoms you describe but the car shouldn't shut off. It may still be a bad coil. How did you eliminate that possibility. It also can be a dirty MAF. 

Profile picture for user refko12311

I have a P0300 code for random missfire and p0301,2,3,6, and 5 which indicates which cylinder is misfiring and p0432 which is cats below threshold.
There is p0410 it says It's secondary air injection and i have no idea what that one means or where is it located
I went to autozone just now hoping that they're gonna give me the reason why is my engine misfiring but it said no solution. I have no idea what to do next and my car shut off only once btw as i was pulling over to shut it off and turn it back on because then the engine comes back to normal. I appreciate you trying to help me. What do you think is it cats should i change my O2 sensors first?

Profile picture for user MBFanatic

You have misfire codes for both cats. Which makes me think it is not the cats. Very unlikely they both have gone bad at the same time. What you can do is unplug the upstream o2 sensor and see if car drives better. Or take the car to a muffler shop to do a backpressure test. If you have a Exhaust Back Pressure Test  gauge you can perform the test yourself. Remove upstream O2 sensor and plug the test kit. That will allow you to tell if the cats are clogged. 

My guess would be a bad mass air flow sensor or maybe a vacuum issue.

 

Btw, the M112 is very solid engine. So don't give up yet.  

Profile picture for user refko12311

Thank you very much and im most definitely not giving up it's my baby that keeps braking all the time ??

Plain text

  • Allowed HTML tags: <a href hreflang> <em> <strong> <cite> <blockquote cite> <code> <ul type> <ol start type='1 A I'> <li> <dl> <dt> <dd> <h2 id='jump-*'> <h3 id> <h4 id> <h5 id> <h6 id>
  • No HTML tags allowed.
  • Lines and paragraphs break automatically.
  • Only images hosted on this site may be used in <img> tags.
The content of this field is kept private and will not be shown publicly.

2010 Mercedes ML350 BlueTec fuel leak (Left tank)

0
tarheel3759
6 days 20 hours ago
Mercedes » M-Class » 2006-2011

check liquid level

0
equintquant2
6 days 21 hours ago
Mercedes » C-Class » 2001-2007

Mercedes Benz clk w208 supercharger

0
timcolledge
1 week 2 days ago
Mercedes » CLK-Class » 1998-2003

Dodge. Journey 2015

1
TennesseeRebel
1 week 2 days ago
Dodge » Journey » 2009-____

Is it my ignition switch?

0
lcserna0423
1 week 2 days ago
Dodge » Caravan » 2008-____

2009 Mercedes e350 rwd 80 k miles

2
lucapuca
1 week 5 days ago
Mercedes

2006 chrysler crossfire convertible top problem

2
daisyblemmons
2 weeks 1 day ago
Chrysler » Crossfire

Problem with automatic start

4
abchris
2 weeks 1 day ago
Audi » A3 S3 RS3 » 2015-____

Mercedes ML350 bluetec sputter misfire

1
Nmerc
1 week 4 days ago
Mercedes » M-Class » 2012-____

Fuel issue

1
Andrew Williams.90
1 week 5 days ago
Buick » LeSabre » 2000-2005

Brake system

2
tammyduran
2 weeks 1 day ago
BMW » Z4 » 2003-2008

Best Shocks for Grand Cherokee

2
JohnSmith75
2 weeks 2 days ago
Jeep » Grand Cherokee

W212 AMG seat swap

1
GPone
1 week 6 days ago
Mercedes

do you need to register new battery on 2006 z4???

1
jdgallo
1 week 6 days ago
BMW » Z4 » 2003-2008

Mercedes CLA 250

4
jc71
2 weeks 2 days ago
Mercedes

CHANGING DASHBOARD LANGUAGE

2
Master
2 weeks ago
Volvo » S40, V40

2004 f150 wont start

1
dldiggs2
2 weeks 3 days ago
Ford » F-Series » 2004-2008

2006 chrysler crossfire convertible top problem

1
daisyblemmons
2 weeks 1 day ago
Chrysler » Crossfire » 2004-2007

Intermittent issue with low cranking power when ESC OFF light comes on

1
SteveJ27
2 weeks ago
Hyundai » Elantra » 2007-2010

Apple car play for 2016 e350 4matic

2
Triangle123
2 weeks ago
Mercedes » E-Class » 2010-2016

User has not asked any questions.