Cat on CLK320 petrol (W209)

[the_player]

I think one of these has gone, usual rattly tinkly noise when at certain revs and makes a rattly noise when you tap it when the car is up on ramps. It is only 1 that has gone, questions is....

- Can you just replace the one
- How much does it usually cost (I know these things aren't cheap)
- Can you just de-cat it and bin the thing off completely, seems to be a few threads suggesting this on here.

 

[BlackC55]

You can remove the last two cats and It will be ok for MOT.

 

[colechelle]

That engine also can suck bits of the CAT back in to the engine, wouldnt use it unless you have to until fixed!!

 

[BlackC55]

That pipe turned up right Col.

Its a bitch to fit.....

 

[colechelle]

I know mate, i did it the other day!!!!!! good result then!!!

 

[the_player]

Does it make sense to get both removed even if only one has gone ?

 

[BlackC55]

yes.

 

[the_player]

I know its a bit of a how long is a piece of string question, but the engine management light has come on now. Could this be related ?

 

[jaymanek]

yes as the readings of the exhaust CO are too high post cat due to it being damaged.

 

[the_player]

Hmmm... think it might be a bit more than this. There is a real loss of power - almost as if someone has stuck a banana up the exhaust...

 

[the_player]

If I put the car in park and then rev the engine it won't go above 4K revs anymore. Is this symptomatic of bit of cat in the engine or could there be another explanation ???

Either way, its in the garage tomorrow to have the cats removed so I suppose I will find out then.

 

[Adam230K]

no mercedes goes over 4k when revved at stand still.

 

[the_player]

haha! Oh well, that was a bad test then!

What it does do though is really struggle and flashes the engine management like like mad when you full throttle it whilst driving. half throttle/normal driving is fine, but it can't handle the full throttle.

 

[the_player]

Well, just got the car back after having the back 2 cats removed and the car is now running sweet. Must have been a bit of the dodgy cat blocking the exhaust.

 

[BlackC55]

Glad its sorted

 

[the_player]

Yeah, I'm glad that problems sorted. Was really worried that the cat may have been sucked back into the engine, but to be honest the more I think about it I don't see how that can happen anyway ??

Eitehr way - the car is fixed and seems to be a bit quicker too...

 

[rajinder_1]

im pretty sure that bits cant be sucked back to the engine as i was told that the pipe has a filter to stop that happening (or something along those lines).

Have you noticed any difference in noise? did you put a straight pipe through or just remove the element and weld back up???

 

[the_player]

I (well someone at the garage) cut both of the cats out and then placed 2 straight through pipes where they had been.

It isn't really any noisier to be honest, just a little bit more responsive and bit quicker higher up the rev range.