Catalytic converter replacement.

The Check Engine light is on on my Mercedez-Benz. The car has less than 49,000 miles, but the dealership says I need to replace both the front right and left catalytic converters.
Experienced mechanics share their insights in answering this question :
This would depend on the code that is retrieved from the check engine light. It never hurts to get a second opinion. I would recommend having another technician, such as one from YourMechanic, come to scan your vehicle for trouble codes. The diagnosis will be based on the codes that are present in the system. It is = possible that the oxygen sensors or the catalytic converter may need to be replaced.

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Labor costs are estimated between $226 and $286 while parts are priced between $1,297 and $1,297.
Mercedes Benz Catalytic Converters

While Mercedes Benz`s are expensive- their catalytic converters could be both low and high value. These cars typically have 1-2 catalytic converters, and Mercedes does an excellent job of having serial numbers stamped right on the units.

Driving with A Failed Catalytic Converter

If you`re noticing slow powertrain performance, reduced acceleration, a smell of rotten eggs or sulfur from the exhaust, dark exhaust smoke, or extreme heat from under the vehicle, these are symptoms of a clogged Catalytic Converter, and it should be replaced quickly.

Additionally, driving without one can be dangerous because your vehicle won`t accelerate properly. You may also notice that your car has lesser power in lower gears. Therefore, replacing the catalytic converter is important and should not be delayed.
A new catalytic converter should last for around 10 years but, as with most other vehicle components, the exact lifespan can differ. Mileage and engine tune can impact on the durability of the item, so it`s worth checking the condition after 50,000 miles.
There are two converters in each pipe.
There are 3 catalytic converter types that you may come across: Two-way: A two-way catalytic converter is often referred to as an “oxidation” converter. It oxidizes carbon monoxide and hydrocarbons. Three-way: A 3 way converter does the same as a two-way, but also reduces nitrogen oxides to nitrogen.
Yes, any internal combustion engine can run without catalytic converters.
Most catalytic converter failures fall under one of three categories: Overheated, melted or broken converters.
The catalytic converter is an important part of your Mercedes engine. It`s responsible for converting dangerous chemicals into less harmful ones before they leave your car. The converter uses high pressure and temperature for this conversion, and this can lead to wear.
Catalytic Converter Mercedes-Benz C – CLASS

The exhaust catalyst or catalytic converter minimizes pollution and reduces the exhaust fumes emitted by your C – CLASS. Its lifespan is approximately 80,000 miles. This average lifespan may be reduced in the case of engine malfunction.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

Check Engine light comes on, mechanic replaced o2 sensor but light still comes on.
ANSWER : Hi there:

If the mechanic completed the O2 sensor replacement, reset the codes and the error code was triggered again, it is possible that the catalytic converter is damaged and needs to be replaced. However, it’s also very common for the electrical harnesses that power these sensors to become frayed, damaged or faulty; which can also trigger the check engine light. It’s not advisable to drive a vehicle with a damaged catalytic converter for extended periods of time, as it can cause damage to internal engine components.

Do you have to replace the catalytic converter when replacing a cracked exhaust manifold?
ANSWER : Hi there. Although they are connected together, they are separate components that are typically sold and installed individually. Although it’s always a good idea to replace the catalytic converter the same time. If the exhaust manifold is cracked, I would simply replace the exhaust manifold.

Is it possible to fix a clogged catalytic converter without replacing it?
ANSWER : Hi there. In general, there is not an effective way to clean a clogged catalytic converter. There are several aftermarket products that claim to do so, but they typically cause more issues with fuel system components that I would never recommend them to be used. You should read this article on ways to diagnose a bad catalytic converter as a reference. It might be a good idea to read these two articles on the OBD-II trouble codes, the P-0306 trouble code and the P-2241 OBD-II code so you can see the multiple possible source of these codes.

Changed catalytic converter, no lights on dashboard, but codes for catalytic converter & O2 sensor still remain
ANSWER : Hi there, thanks for writing in. I am not sure why you changed your catalytic converter. Assuming you had a P0420 code, replacing the catalytic converter should of resolved that code. The codes originally stored need to be cleared. The fact your check engine light remains off tells me, you may have fixed the problem. Try disconnecting the negative battery terminal for at least 2 minutes, reconnect. Start and drive the vehicle for 10-15 miles. Re-check for codes. If a code returns on the first drive cycle (pending code), a problem still exists. The check engine light should come back on (the next drive cycle) if, the fault is recognized by the computer. An exhaust leak before the oxygen sensor will cause O2 sensor and catalytic converter codes. If you are having trouble identifying the fault, consider having an expert automotive technician from YourMechanic come to your home or office to inspect and diagnose this issue for you, and make or suggest any repairs as needed.

Does traction control depend on catalytic converter functioning properly?
ANSWER : You are right, the traction control system is not related in any way to the exhaust system (e.g., the catalytic converter) in the vehicle. Traction control involves wheel speed sensors, the ABS system, and electronic controllers. If there is a problem with the traction control system on your vehicle, it is likely that diagnostic trouble codes have been stored and those codes will provide the key clues to finding, and repairing, the fault in the system. A certified Mechanic, dispatched by YourMechanic right to your location, can perform a traction control system diagnostic and let you know of the required repairs. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

Need to replace catalytic converter on my car
ANSWER : Hi there, the P0420 code could have many different causes.

With the catalytic converter, it is typically best to purchase it from the dealer. It really depends on your local regulations though. If your regulations allow for aftermarket converters, then you should try your local exhaust shop as they should have a universal replacement. If you need the OE converter then you will need to go to the dealer for it.

If you need further assistance with this, a certified technician can come to your home or office to supply a catalytic converter and install it for you.

I need to replace my catalytic converter and I wanted to see what are the main parts I will need to buy that comes with it?
ANSWER : The parts required to change out a catalytic convertor will really depend on what type of converter is going to be used. There are factory type replacements that will use a flange and just get bolted into place, that will require a new flange gasket and pipe clamp. Or there are aftermarket replacements that will require the pipe to be cut, and either welded, or clamped into place. Other than that, I would suggest that this is the perfect time to replace the oxygen sensor. Keep in mind, when removing the flange from the back of the engine, it is fairly common for the bolts and/or studs to break, due to all of the heat cycles that are associated with the exhaust/converter. As far as the rough starting issue, I would check the timing chain and tensioners. It sounds like there may be a possible issue with chain tensioner, and this can cause all kinds of problems, especially throwing off the timing and causing rough starting and running issues. If any of this sounds like something you could use a hand in diagnosing and/or repairing, contact a certified mechanic, like the mobile mechanics at YourMechanic.com.

How difficult would it be to replace the catalytic converter on my 1997 Chevy Blazer?
ANSWER : Hello. If the exhaust system is original, that is if it is about 20 years old, you will probably end up replacing the entire system, consisting of the "Y" pipe coming off the manifolds, the converter, muffler, and tail pipe. The reason for this is that the catalytic converter mates to the "Y" pipe on one end and to the muffler on the other via flanges with three bolts per flange. These flanges both rust shut and are typically weakened once bent (installed) years ago and thinned out by rust.

You can sometimes attempt to salvage existing parts by using aftermarket flanges and/or split flanges but if the rest of the system is even as little as 5 years old it is not worth it. Also, in your configuration the converter is not set up with straight pipe on either end making retrofit to the existing system less convenient.

If you do replace the whole system, the most critical task is to remove the three nuts on each manifold flange stud without breaking or damaging the thread on the stud. If you haven’t done this before, I recommend that you at least observe the procedure while someone trained completes the job, and then next time around you may have the confidence in taking on this type of job after seeing how it is done. It is a bit of work, and unless you have dealt with exhaust fasteners before, it can be tricky. If you would like a professional handle this, a certified professional from YourMechanic can come to your car’s location to inspect the rattle and replace the catalytic converter for you if necessary.