How JustAnswer Works:

  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.

Ask Marty Your Own Question

Marty
Marty, ASE Certified Technician
Category: Mercedes
Satisfied Customers: 53153
Experience:  Bosch Certified Master Technician with over 35 years experience in the automotive industry.
13230946
Type Your Mercedes Question Here...
Marty is online now

I have just taken my Mercedes CLK for mot test and it failed

Customer Question

I have just taken my Mercedes CLK for mot test and it failed the emission test.
The garage then advised that the catalytic converter, the O2 center and the Lamdar centre(not sure of the correct spelling) needed to be replaced. Despite replacing all these part, it still failed a retest on emission. Now the garage has said they cannot figure out why.

Can anyone help explain what could be causing the emission failure.

Many thanks.
Submitted: 3 years ago.
Category: Mercedes
Expert:  Marty replied 3 years ago.

Marty :

Hi, my name is Marty. Is your check engine light on or had it been on previous to the repair work?

JACUSTOMER-wo9wrzvm- :

Yes it had been on prior to going in to the garage but that was because of transmission problem which i have had for a while due to leaks. I usually top up each time it goes into safe mode and that solves the problem until the oil level goes low again.

JACUSTOMER-wo9wrzvm- :

sorry hi i am peter

JACUSTOMER-wo9wrzvm- :

Hello! are you there.

Marty :

Sorry Peter I had to step away. Can you possibly post the fault codes that were stored in the engine control module?

JACUSTOMER-wo9wrzvm- : I have no engine code. The garage cannot provide any
JACUSTOMER-wo9wrzvm- : I mean fi have not been provided with a fault code
Marty :

Hi Peter, it will be impossible for me to advise you without the fault codes or the mot test results. Can you contact the shop and get the information?

JACUSTOMER-wo9wrzvm- :

The diagnostics did not return any fault code, but the car still failed on emission despite the garage replacing all the part I have earlier mentioned.This is why i came on your site to find out the possible reason(s) and solution. I was hoping this is a known problem with CLK and that a specialist mechanic would help provide a solution. I however would get the MOT test result tomorrow, and maybe it would provide some additional info.

Marty :

Hi Peter, if your check engine light is on there are definitely fault codes stored in the computer. If you can post the results of the MOT test I can advise you.

JACUSTOMER-wo9wrzvm- :

ok. I will provide that info by tomorrow.

Marty :

Sounds good, I'll wait to hear from you.

What Customers are Saying:

 
 
 
  • 9 dollars, 2 hours of my time, and I drove away. Your diagnosis was right on the mark. Thank you so much. Phil
< Previous | Next >
  • 9 dollars, 2 hours of my time, and I drove away. Your diagnosis was right on the mark. Thank you so much. Phil
  • Lurch. Thank you very much. I had real doubts about this website but your promptness of response, quick followup and to the point answer with picture was incredible. Charles
  • As a single woman, I really appreciate an excellent and affordable opinion.
    Thank you Geordie, I will not hesitate to contact justanswer in the future!
    Sue
  • Another great insight to what may be the problem. I will have my mechanic take a look at it tomorrow. Thanks again, Frank...you do indeed know your stuff. Jim
  • I would (and have) recommend your site to others I was quite satisfied with the quality of the information received, the professional with whom I interacted, and the quick response time. Thanks, and be sure that I'll be back whenever I need a question answered in a hurry. Stephanie P
  • Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help. Mary C.
  • This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!! Alex
 
 
 

Meet The Experts:

 
 
 
  • Matt

    Matt

    Mechanical Engineer

    Satisfied Customers:

    482
    BEng hons Mech engineering, in auto industry 22 years
< Last | Next >
  • http://ww2.justanswer.com/uploads/35/350matt/2012-6-7_182356_matsavatr.64x64.jpg Matt's Avatar

    Matt

    Mechanical Engineer

    Satisfied Customers:

    482
    BEng hons Mech engineering, in auto industry 22 years
  • http://ww2.justanswer.com/uploads/EU/eurotec/2012-6-11_13153_mpjaphoto.64x64.JPG Marty's Avatar

    Marty

    ASE Certified Technician

    Satisfied Customers:

    21371
    Bosch Certified Master Technician with over 35 years experience in the automotive industry.
  • http://ww2.justanswer.com/uploads/MI/mikeamechanic/2013-4-2_175558_photo.64x64.JPG mike_a_mechanic's Avatar

    mike_a_mechanic

    Mercedes Mechanic

    Satisfied Customers:

    116
    17 years experience as a auto mechanic, foreign and domestic.5 years running my own repair business.
  • http://ww2.justanswer.com/uploads/MB/MBpaul/2013-8-21_204936_paul.64x64.jpg MB Paul's Avatar

    MB Paul

    Mercedes Technician

    Satisfied Customers:

    212
    Mercedes Benz Qualified Diagnostic Technician
  • http://ww2.justanswer.com/uploads/IN/indytech/2013-8-8_102717_SantoDomingo146598x6402.64x64.jpg Greg's Avatar

    Greg

    Technician

    Satisfied Customers:

    1080
    Automotive diagnostic tech
  • http://ww2.justanswer.com/uploads/TE/techmachine/0601821347169_717372168_8940977_39623330_o.64x64.jpg Ross's Avatar

    Ross

    Diagnostic and repair technician

    Satisfied Customers:

    453
    Licensed diagnostic and repair technician