p30amg08

How do you know a catalytic converter is going bad? I took my car to the dealership for a different issue and when we started it up this morning on a cold start and started driving it, it was making a weird noise sounded like it was coming from underneath the car they looked at it and said that the catalytic converter is going bad. Never heard this noise before, when I started the car the oil temp showed 5C, they're telling me its 3400 to replace it I'm just curious as to what's actually going on I have a hard time believing that converter cost that much

hpV12

Do you really have to ask if 3,400 is a fair price for cats?

p30amg08

Just trying to get some help here bro. I kinda figured 3400 is out of this world, just wondering how does one know it's bad what kind of sound would it make, are they ever covered under warranty from MB? I also have extended Fidelity platinum warranty but the SA said that it's not covered under that, just wanted to see what you all think?

novae500

check the clean air act/emissions related, cats are supposed to be covered for 10yrs/80k miles and fixed for free if they fail. Depending on if you have any mods, MB might not cover it.

I replaced my cats after getting rattling noise, then stinky egg smell after driving it. Ended up getting aftermarket cats from performance curve online

turbo97se

Interesting … I had thought it was 10 years 100K miles - but never confirmed it.

OP could've looked this up for yourself or asked your warranty company if the Federal laws on emissions cover it:

If you are in any State other than California, consider switching to aftermarket cats .. way cheaper.

Then looked this up on Mercedes website. Of course, if you read it closely "certain parts" are covered … which means other parts are not or possibly certain parts are covered for even longer … good job from the Lawyers on wordsmithing

p30amg08

thank you guys very much for the info so far. Weird thing is that my car was not making any weird noise or smell when i dropped off my car (still no smell) So IDK what happened in the one night the car was at the dealer. He said when I come in again he will show me where the noise is coming from...Can you visually look at the cats and know its bad. I am sorry I am completely oblivious to this part of the car. The only MOD i have is a resonator delete....Would that VOID the warranty?? The SA was telling me that Fidelity might cancel my warranty because of that?? Thanks in advance for your help guys, it means alot.

novae500

he Performance Warranty covers repairs which are required during the first 2 years r 24,000 miles of vehicle use (whichever first occurs) because the vehicle failed an mission test. Specified major emission control components are covered for the first
8 years or 80,000 miles (whichever first occurs). If you are a resident of an area with
n Inspection and Maintenance (I/M) program that meets federal guidelines, you are
ligible for this warranty protection provided that:
• Your car or light-duty truck fails an approved emissions test; and
• Your vehicle is less than 2 years old and has less than 24,000 miles (up to
8 years/80,000 miles for certain components); and
• Your state or local government requires that you repair the vehicle; and
• The test failure does not result from misuse of the vehicle or a failure to follow the manufacturers’ written maintenance instructions; and
• You present the vehicle to a warranty-authorized manufacturer representative, along with evidence of the emission test failure, during the warranty period.

http://www.epa.gov/obd/pubs/420f09048.pdf

p30amg08

Thanks bro. I saw this and asked the dealer he said since I removed or deleted the resonator, that voided my emissions warranty. That sucks ***. I don't think deleting the resonator has any effect of the left catalytic converter.

What do u guys think?

Critter

Denial does not work when dealing with warranty issues. Someone modified the system so that gives the dealership the ability to use the blanket statement, No you are not covered!

sunil517

It might be a shield or something is making the noise if they worked on the car.
Remember these car make a different sound when cold until the air pump shut off...
Do you have a CEL?

sunil517

BMW Dealer installed new clutch on M5 swap the O2 rear plug around and said new cats were needed... They installed them for free..still the same issue.. Car came home and I was the plugs around and I was good to go...
I am not sure if MB plug left bank to right bank can be swap...
but can not see CATs going bad just like that...
you gots to have a CEL...of lots of misfiring to damage the CATS

p30amg08

No CEL. Car runs strong. Not sure what the plugs are. Again I am new to this. Still learning. I need to get under the car and look and take pics. If it will help I can take pics. Can you see visually if i post up pics?

sunil517

and take it to a local shop to look over..
If the CATs are bad a CEL should show up..
I think they must have drop a heat shield make some noise and to rip you off...
Dealer is the last place to take your car unless it is covered...
ANY Dealer..MB BMW VW NISSAN HONDA>. dont care.. All are looking for a prey

p30amg08

Sunil thanks man, that helps alot. I had a nice little chat with the dealer today. And I'll take my car to an indy shop see what they say.