[W212] Catalytic Converter clogged - Check Engine ON

[cezar]

three weeks ago had a check engine light ON on a very hot summer day and a long trip. no symptoms as I was able to tell. called my delaership and made an appointment. by next day the light was off and the dealership said just don't come now and see if it happens again.

fast forward to last weekend, driving in town, again really hot (if it makes any difference) and check engine light ON and sudden loss of power. the car won't rev over 2000 rpm. went back home slowly. next day light still ON. took the car to service today. after diagnosis: catalytic converter clogged, needs replacement. the cost of it is just over 2000 euros (OMG i know)

now this is a car for me and I intend to keep. i know the converter is hell expensive so I guess the best bet would be to have it replaced. my concern is if it's just a regular failure (i hear they last in average 10 year and 160.000 km, and I'm 10 with 270.000 km) or if it's something else that is generating this. i wouldn't wanna replace it and than see that i have other failures which maybe will break this again.

anyway they called me to get the car back now. they say it's ok for casual driving in town and no additional harm can be done. i'll just have it parked home and that's it. and in the meantime I have to take a decision. but looks pretty straight forward though. anyway they need to order the part which is 1-2 weeks delivery.

any piece of advice here? similar experience, side effect etc?

thanks guys

 

[markjay]

There are various products on the market that supposedly clean the cat, whether they work is debatable, but given where you are now, no harm in trying.

That said, cats usually get 'consumed', or they brake-up internally and clog the passage of the exhaust gasses, in which case the only solution is a new cat.

You can also have the cat removed and the ECU updated, but you'll need to check if this is legal where you are.

 

[cezar]

short update

just took the car back from the dealership. surprise: the check engine light is OFF and it seems to behave normally now. wonder why the come and go of this!

anyway got also the xentry report which says:

Module: N3/10 Motor electronics MED97 for combustion engine M272 ME​

Fault: The efficiency of the NOx storage catalytic converter (cylinder bank 1) is not sufficient (Fault 0466)​

​

it's curios that the odometer reading says 60k'ish which is loooong time ago. but the fault is marked as current and stored.

anyway, now I'm waiting for some feedback from the dealership and will see how this goes.

one other thing: can help to notice that everytime this happend it was really hot outside (37C like the official temp in the news, in traffic I guess much higher). today there are 18C.

LE: remembered that I had some old xentry report from like more than half year ago. strange to find that it also had the Fault 0466 in it but than no one said anything about it. strange :|

 

[cezar]

status update

kept driving (easy drives city side) and the light went off couple of days and than back on. now it's off again. and when it's off all seems normal. wehn on you can feel the very low power.

anyway got a recommendation to take the car to a local service to try a cleaning. goona try this tommorow. they'll take the thing apart and see the "thruth" and what can be done. cost wise is like 10-15% of the officiall bill. apart for the inconvenience of distance and possible two day in the shop i think why not.

but it's strange how it comes and go now... any hints on this behaviour anyone? ot this is the clear sign is dying?

 

[MrGreedy]

Oh boy. I've just checked out how much a catalytic convertor is for my E350 CDI. €900. I didn't check if I need 2.

I was hoping to keep the car a good while, but this seems like a crazy price!

For my w203, it was £300 a side, which was a single pipe with 2 cats each side.

 

[Larkone]

Had a partially blocked cat on the wifes BMW 3.0 petrol and it was affecting the throttle response, a slight hesitation when accelerating. Got it nicely warmed up and then ran it at around 3500 rpm on the motorway. Very impressive cloud of brown smoke for a couple of miles and a lot of black soot over the back of the car when I stopped.

Ran perfectly after that, passed an MOT with a comment from the tech about how clean running the engine was (65,000, 12 years), saying it was effectively the same as a new engine. The reason for the problem was a life of the car living in London and then in our ownership being used as a shopping trolley and never getting properly warm.

 

[MrGreedy]

That's a good tip Larkone and worth remembering.
For the replacement on both sides for my W203, it was due to break up of the catalytic converter causing blockages within itself. Unfortunately no amount of use will sort it if that goes wrong, but you could here the cat rattling slightly, so there was other tell-tale signs.

 

[cezar]

But why the on and off?

 

[14emerc]

One thing to ensure is that you have the correct engine oil spec for the car. If it says Low Ash C3 oil then thats what must be used. You can damage and shorten the life of the cars cat by adding the wrong oil. A good run using a motorway a few times a year will bring the engine and exhaust system up to working temperature and allow the cat to carryout a regeneration. Both of the above go hand in hand especially if your car lives and works in a city environment.

 

[MrGreedy]

When my cat(s) were breaking up, sometimes it would block, other times it was okay, as the 'bits' moved around in the cat. I'm not saying it's the same thing, but it was intermittent when I had a problem.

 

[cezar]

How many are there? Isn’t it just one?

 

[MrGreedy]

How many are there? Isn’t it just one?

I'm not 100% sure. I think one. On the W203 V6 petrol, it was 2 cats (as a single unit), each side, so 4 in total. £300 a side from Merc for the 2 cat pipe. Nothing like the price of the cats for the 212.

I now have the diesel V6 in the E350 CDI S212, and the cat bolts directly to the DPF from looking at the parts diagram (below), and I'm assuming the top bolts directly to the turbo outlet but I don't know for sure. At the prices I've found, I seriously hope it's only one.

Part No. 10 for me. Part number 5 (the DPF/cat assembly) states not available as a single unit and to buy the constituent parts separately and assemble off the car.
A2124901214 (part number A2044904736 also listed, so might be a cheaper alternative for me if I ever need one).

 

[cezar]

Just got off the phone with the service. Looks like there are two cats which come together with DPF. They took them all out and sent to cleaning. Will see how that goes. Hope they don’t charge as a new cat though.
Even so... not sure how much a cleaning should last

 

[cezar]

update

got my things cleaned. they told me like one is 100% ok and one 60% ok because it has some melting stuff in there. left with the car it definitely felt like reving much smoother. all good till after 3-4 days when check engine back ono. all going slow. the same day in the evening went off again but for a few km only. got back home and next day all looked good and looks good still. so very strange

one thing i noticed though is that i think that under the car it gets way hotter than other times. i just feel it when i get out the car. and it felt like the engine fan blows way harder when back in the garage. on the dashboard oil temp looks fine. don't know just saying.

now all works ok but who knows till when

 

[MrGreedy]

If it's hot when you have stopped a journey, it's probably an interrupted DPF regen.

Some bedtime reading:

DPF Regen - Install in-cabin indicator light | Engine

Hi, In my rubbish Insignia (soon to go) I've installed a 12v LED wired directly into the driver's heated wing mirror positive and negative wires. The LED is neatly hidden behind the tweeter speaker grill in the front corner of the door, and lights up blue whenever the heated wing mirror are...

forums.mbclub.co.uk

 

[geraldrobins]

If it's hot when you have stopped a journey, it's probably an interrupted DPF regen.

Some bedtime reading:

DPF Regen - Install in-cabin indicator light | Engine

Hi, In my rubbish Insignia (soon to go) I've installed a 12v LED wired directly into the driver's heated wing mirror positive and negative wires. The LED is neatly hidden behind the tweeter speaker grill in the front corner of the door, and lights up blue whenever the heated wing mirror are...

forums.mbclub.co.uk

OPs car is petrol so wont have a DPF? I didnt think catalytic's regenerated as such but I may be wrong. I've read that they continually burn off deposits.

 

[cezar]

Mine has DPF. It’s bonded together with the CAT. Actually one set on each side. The cleaning process was done for the entire ensemble. So theoretically all was cleaned.
Wanted to attach a short video of how the cleaning goes but can’t upload videos

 

[Londonscottish]

Mine has DPF. It’s bonded together with the CAT. Actually one set on each side. The cleaning process was done for the entire ensemble. So theoretically all was cleaned.
Wanted to attach a short video of how the cleaning goes but can’t upload videos

Minor point; DPF = Diesel Particulate Filter.

If yours is a CGI it'll be a GPF or PPF (Gasoline or Petrol Particulate Filter).

Doesn't make it any less annoying, though.......

 

[Uky]

If this is a 350 CGI V6 3.5 Litre Petrol engine (just to make sure...)

While you are at it: Open the hood and remove the engine air filter assembly.
You will need to snap the rear fastener a bit backward.

When the engine top is accessible, you will find a black hose running from the front
of the engine, connecting to a Y-shaped joint to a stiff hose (tank vent)
and then running to a connection to the main inlet below the air mass meter.

Lift this black hose up and check for cracks, particularly underneath the Y-joint.

This is a common fault that developes between 100,000 and 160,000 kms
and the error code (among others) is wrong air/fuel mixture, one or both banks.

Checking this with Xentry real time data from the lambda sensors
will reveal an unstable feedback voltage.

The hose is some € 26-30. You will need to lift the air mass meter
which can be a bit tricky (prevent the metallic dust particle grid
from getting loose and fall down into the sensor ass:y).

 

[ChrisEdu]

Had a partially blocked cat on the wifes BMW 3.0 petrol and it was affecting the throttle response, a slight hesitation when accelerating. Got it nicely warmed up and then ran it at around 3500 rpm on the motorway. Very impressive cloud of brown smoke for a couple of miles and a lot of black soot over the back of the car when I stopped.

Ran perfectly after that, passed an MOT with a comment from the tech about how clean running the engine was (65,000, 12 years), saying it was effectively the same as a new engine. The reason for the problem was a life of the car living in London and then in our ownership being used as a shopping trolley and never getting properly warm.

Sounds like the mythical Italian tune-up.