Mercedes

Have Mercedes Questions? Ask a Mechanic for Answers ASAP

Ask an Expert,
Get an Answer ASAP!

Mercedes

This is a follow-up to my previous questions regarding

Customer Question
replacement of the cat converters...
This is a follow-up to my previous questions regarding replacement of the cat converters on my 2007 GL450. As I stated in my last comments, I purchased a coder reader and am attempting to troubleshoot the issue myself before returning to the shop. Based on the live data readings I've seen, I suspect I might have O2 sensor issues. Can you suggest possible troubleshooting tips for o2 sensors?
Submitted: 6 months ago.Category: Mercedes
Show More
Show Less
Ask Your Own Mercedes Question
Answered in 48 minutes by:
7/28/2017
Mercedes Mechanic: Lou P. master tech, Mercedes Technician replied 6 months ago
Lou P. master tech
Lou P. master tech, Mercedes Technician
Category: Mercedes
Satisfied Customers: 5,503
Experience: 15 years master certified 100% fix rate and have access to factory radio codes, wiring, and instructions.
Verified

Hello, my name is***** and i will do my best to assist you.I am going over your story now and will reply back soon with some info,thanks!

Ask Your Own Mercedes Question
Mercedes Mechanic: Lou P. master tech, Mercedes Technician replied 6 months ago
Can you tell me the code numbers again and the scanner you are using ?
Ask Your Own Mercedes Question
Customer reply replied 6 months ago
I'm getting codes P0420 and P4030. I'm using an Autel AL419 scanner. Despite your warning, I cleared the codes and now the O2S monitor test will not complete. Hence, my concern that I might have sensor problems.
Mercedes Mechanic: Lou P. master tech, Mercedes Technician replied 6 months ago
Ok :) let me see what I can get you , it may be later tonight .
Ask Your Own Mercedes Question
Customer reply replied 6 months ago
OK, Thanks
Mercedes Mechanic: Lou P. master tech, Mercedes Technician replied 6 months ago

ok aaron sorry for the delay, i cannot locate the p0420 or p0430 codes in the mercedes scanner, still from what i find the converters are the issue i looked at the last info you have given me on our other chat and its still possible that the o2s are lazy and not reading correctly, thats always a possibility, im trying to find more info on these codes, the problem is that in mercedes we can have a fault code with a suffix of 01 through 04 and they all mean something different, that is the way they are getting around the standardized obd 2 laws it seems. im still looking my friend I will try and find some info as soon as i can. Lou

Ask Your Own Mercedes Question
Customer reply replied 6 months ago
OK, Thanks for the help!
Mercedes Mechanic: Lou P. master tech, Mercedes Technician replied 6 months ago

AAron I cannot get you anything better on these codes. the best i can say is it may be worth it to replace the o2 sensors and see if the codes go away, if not you will need catalytic convertors. I will open this up to see if another expert can help. Lou

Ask Your Own Mercedes Question
Mercedes Mechanic: mike switzer,
 replied 6 months ago
mike switzer
Category: Mercedes
Satisfied Customers: 727
Experience: lead diagnostic tech at Aamco
Verified

whenever codes p0420 or p0430 show up it means the o2 sensors and reading properly and realizing the catalytic converters and not working efficiently. i have yet to see a vehicle of any make to this day that had those codes and it was not a bad cat.

if you have an infrared thermometer you can measure the input and output temps of the cat after a long drive. the output should be significantly hotter. around 600-700 degrees i would say if it is not that hot on the output the cat is not working as it should.

Ask Your Own Mercedes Question
Customer reply replied 6 months ago
While not the answer I was hoping for, I do appreciate the advice.
Any idea why the o2 sensor monitoring test will not complete after erasing the codes?
Mercedes Mechanic: mike switzer,
 replied 6 months ago

because the cat is not working properly. the test will complete when it verifies everything is withing passing range. but if it senses an issue then it will not complete and will eventually re-throw the cat codes.

Ask Your Own Mercedes Question
Mercedes Mechanic: mike switzer,
 replied 6 months ago

i apologize for the delayed response i had to leave early for an emergency.

Ask Your Own Mercedes Question
Customer reply replied 6 months ago
That makes sense if the cat system test did not complete. Why would a cat problem prevent testing the o2 sensors?
Mercedes Mechanic: mike switzer,
 replied 6 months ago

the o2 sensors are what complete the cat test. so if it cant complete the cat test it it stops running all other test.

Ask Your Own Mercedes Question
Customer reply replied 6 months ago
The cat test completed and threw the p0420/30 codes. All other test completed except the o2 sensor test. At this point, i see no other option other than replacing cats and o2 sensors.
Mercedes Mechanic: Lou P. master tech, Mercedes Technician replied 6 months ago

Aaron i would start with the 02 sensors first. those are the lesser expensive of the two, see if that helps.

lou

Ask Your Own Mercedes Question
Mercedes Mechanic: mike switzer,
 replied 6 months ago

if you have no further questions at this time i would appreciate if you took a moment to leave me a rating. as lou has already opted out a while ago.

Ask Your Own Mercedes Question
Was this answer helpful?
Ask mike switzer Your Own Question
mike switzer
mike switzer
mike switzer
Category: Mercedes
Satisfied Customers: 727
727 Satisfied Customers
Experience: lead diagnostic tech at Aamco

mike switzer is online now

A new question is answered every 9 seconds

How JustAnswer works:

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

JustAnswer in the News:

Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.

What Customers are Saying:

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 PElm City, NC

used your service this weekend with "Trecers" help. thank you ,thank you, thank you. replaced an A/C fan motor. Local Auto Zone had part. $15.00 "tracer" fee and $40.00 for parts, I saved several hundreds of dollers at a shop. i will recommend you and use you in the future.

David L.Richmond, TX

9 dollars, 2 hours of my time, and I drove away. Your diagnosis was right on the mark. Thank you so much.

PhilMarysville, CA

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.

CharlesWalnut Creek, CA

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!

SueCharleston, WV

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.

JimCastleberry, FL

Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help.

Mary C.Freshfield, Liverpool, UK

< Previous | Next >

Meet the Experts:

MB Paul

MB Paul

Mercedes Technician

3,567 satisfied customers

Qualified Mercedes Benz Diagnostic Technician - 20+ years experience - Workshop Foreman for Mercedes

Marty

Marty

Mercedes Technician

29,009 satisfied customers

Bosch Certified Master Tech. Over 35 years experience.

Lou P. master tech

Lou P. master tech

Mercedes Technician

5,503 satisfied customers

15 years master certified 100% fix rate and have access to factory radio codes, wiring, and instructions.

Michael Warfield

Michael Warfield

Factory Mercedes-Benz Technician

3,131 satisfied customers

Mercedes-Benz Master Certified technician

Matt

Matt

Engineer

602 satisfied customers

Mechanical Engineer with 23 years experience in the auto industry, 8 yrs in formula 1 engine testing

promerc

promerc

mercedes diagnostic technician

553 satisfied customers

Qualified mercedes diagnostic technician & service team manager , ATA registered Master tech

Hipo64

Hipo64

Mercedes Technician

444 satisfied customers

Work and diagnose electronics on daily basis.

< Previous | Next >

Related Mercedes Questions
I have a 2004 CLK320 Convertible. I drove over a speed bump
I have a 2004 CLK320 Convertible. I drove over a speed bump too fast and my rear headrest went all the way up. How do I get them down. The button on the dash panel won't make them drop when pressed. … read more
Marty
Marty
Mercedes Technician
Associate Degree
29,009 satisfied customers
1996 mercedes benz c220 coolant light came on the other day
hi 1996 mercedes benz c220 coolant light came on the other day it was low added coolant to the resovior and found there is oil in the coolant ionly in the resivor and only abot 25%of the resivor is oi… read more
Lou P. master tech
Lou P. master tech
Mercedes Technician
5,503 satisfied customers
2010 sprinter 2500 no crank several falt coads having to do
2010 sprinter 2500 no crank several falt coads having to do with no CAN messages from ECU. Reading low voltage at relay for ECU (10v) relay buzzes, pulling in and out quickly. Alternator was just repl… read more
Pete
Pete
Independent Auto Technician
Vocational, Technical or Trade Scho
138 satisfied customers
I have 7500 miles on my 17 E300 4 matic 1 has a side bubble.
Hi I have 7500 miles on my 17 E300 4 matic 1 has a side bubble … read more
Pete
Pete
Independent Auto Technician
Vocational, Technical or Trade Scho
138 satisfied customers
Exshaust smell when moonroof is open. 230,000. 1993 300se.
exshaust smell when moonroof is open JA: How many miles are on the car? How has your mileage been lately? Customer: 230,000 JA: What is the model/year of your Mercedes? Customer: 1993 300se JA: Are yo… read more
kalamykid
kalamykid
Pactor automotive
Vocational, Technical or Trade Scho
97 satisfied customers
I have a 2006 E350 Sedan 4-Matic. I'm looking for New Head
I have a 2006 E350 Sedan 4-Matic. I'm looking for New Head lights for the Car. The present Plastic cover is to old and I don't have enough light? … read more
kalamykid
kalamykid
Pactor automotive
Vocational, Technical or Trade Scho
97 satisfied customers
My central locking has stopped working on my sprinter camper
My central locking has stopped working on my sprinter camper van. Neither key will unlock it electronically. … read more
Lou P. master tech
Lou P. master tech
Mercedes Technician
5,503 satisfied customers
I have a 2003 CLK430. The top worked fine until the day it
I have a 2003 CLK430. The top worked fine until the day it stopped working. I checked the trunk and the partition was down. I put it up and made sure the switch looked OK. The top started acting flaky… read more
Lou P. master tech
Lou P. master tech
Mercedes Technician
5,503 satisfied customers
2016 sprinter codes R12/1 R12/2. R12/1 and R12/2. Had seat
Had seat belts lock after hit post and have replaced them… read more
Lou P. master tech
Lou P. master tech
Mercedes Technician
5,503 satisfied customers
Mercedes 2000 clk 320 was not running for 5 weeks, put in
mercedes 2000 clk 320 was not running for 5 weeks, put in new battery, ignition key will not turn. changed battries in key. … read more
Marty
Marty
Mercedes Technician
Associate Degree
29,009 satisfied customers
I want to replace the rear bumper step pad on my 2013 ml 350
i want to replace the rear bumper step pad on my 2013 ml 350 … read more
Pete
Pete
Independent Auto Technician
Vocational, Technical or Trade Scho
138 satisfied customers
My blower motor fan seems to have a mind of its own. The
my blower motor fan seems to have a mind of its own. The level speed indicator says high and sometimes it comes out high but then go to low or medium so it never corresponds to the level you want … read more
Marty
Marty
Mercedes Technician
Associate Degree
29,009 satisfied customers
2006 Dodge/Mercedes Sprinter 3500; I5 2.7L turbo diesel What
2006 Dodge/Mercedes Sprinter 3500; I5 2.7L turbo dieselWhat is the R&R procedure for the A/C compressor?One place tells me to just remove the belt, the A/C hoses/lines, and three attaching bolts that … read more
fordguy4u
fordguy4u
Automotive Tech
Vocational, Technical or Trade Scho
70 satisfied customers
My car (2011 E 350 convertible, car of my life) is behaving
Hi ! My car (2011 E 350 convertible , car of my life) is behaving strangely. Do not recognize it's key … read more
Chad Farhat
Chad Farhat
Owner
Associate Degree
4,664 satisfied customers
Is there a low beam fuse on 2004 E320 - Myself - I've tried
Yes myself - I've tried new light bulb - I've tested with ohm meter and bulb is good and connections to bulb are good … read more
Pete
Pete
Independent Auto Technician
Vocational, Technical or Trade Scho
138 satisfied customers
Wanted to get your thoughts on my 2009 GL 550 lift gate will
Hi Michael, Wanted to get your thoughts on my 2009 GL 550 lift gate will not latch. It goes up-and-down but will not securely latch like it should. After a couple weeks of this, I received a battery a… read more
Lou P. master tech
Lou P. master tech
Mercedes Technician
5,503 satisfied customers
Won't crank or start cooling fan comes on high speed now a
Won't crank or start cooling fan comes on high speed now a key does not work … read more
Stephen, MBA
Stephen, MBA
Master's Degree
166 satisfied customers
Dropped one key put it back together tried to start but. got
Dropped one key put it back together tried to start but. got error message ,left in switch, and ate a hamburger still did not work ,tried good key now it won't work 01 01ml 320 … read more
Marty
Marty
Mercedes Technician
Associate Degree
29,009 satisfied customers
Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Show MoreShow Less

Ask Your Question

x