Question about removing the CAT on E300 Turbo Diesel 1997, 606 - PeachParts Mercedes-Benz Forum

Olivier · #1 03-29-2010, 08:22 AM

The plan was to open the CAT, empty it and re-weld the can the way it was, but I was just told that if I do this it might cause some problems as the empty can is alot larger then the exhaust pipe and this might create gas turbulences/ flows depression(?) as there would be different volumes right after the turbo?
Would it be necessary to weld a similar diameter pipe instead of the larger can or it would be OK just to gutt the can?
Oh, the CAT is just behind the turbo and somewhere here someone suggested that the turbo might spin too fast as a result(?)
Thank you.
Olivier

300SD81 · #2 03-29-2010, 01:01 PM

Weld a pipe INSIDE the cat.

Olivier · #3 03-29-2010, 01:26 PM

The bother is that the top and bottom connections on the can are off and the pipe will be tricky to bent like on the pictures, badly made but it show it.

Olivier · #4 03-31-2010, 04:59 PM

Bump.
As annyone as any idea if emptying the cat and re-welded would be OK?
Just touching the water before I go for it...
Thanks.
Olivier

spock505 · #5 04-05-2010, 02:28 PM

Quote:

Originally Posted by Olivier

The plan was to open the CAT, empty it and re-weld the can the way it was, but I was just told that if I do this it might cause some problems as the empty can is alot larger then the exhaust pipe and this might create gas turbulences/ flows depression(?) as there would be different volumes right after the turbo?
Would it be necessary to weld a similar diameter pipe instead of the larger can or it would be OK just to gutt the can?

Can anyone confirm the best way to approach this?

Will gutting the CAT without installing a pipe cause turbulence hindering gas flow?

TIA

oldsinner111 · #6 04-05-2010, 06:52 PM

If no smog sell you cats for a $100.

EdzBenz · #7 04-23-2010, 03:41 PM

I hollowed out my cat and put it back on the car. I haven't experienced any problems in doing this modification. I did notice that at higher RPMs I do get a little more power when I step on the accelerator. Its not by much though. I haven't noticed any problems at all and have been running it for at least 20K miles. If I were to do it over again, I would have removed the can completely and put in a straight pipe.

Olivier · #8 04-23-2010, 06:13 PM

Thank you for this,
I am still waiting on my mechanic to get some time to do the welding.
Its nice to know that it doesn't cause any bother

All the best.
Olivier

Alastair · #9 04-23-2010, 06:22 PM

No need to open up the cat....

Remove it and use a strong steel bar or large chisel and smash the core out of it--Its a ceramic material and breaks up easily, although may take a little time to break it all small enough to come out of the smaller inlet or outlet.

--Break it up small enough for all the parts to fall out, so its an empty can.

Repair the broken pipe in your pic, and re-fit.

--Job done....

Olivier · #10 04-24-2010, 05:25 AM

This is a great idea Alastair but I don't think I could access the inside, its not a strait line and goes up 90 degres right after the elbow.
Another thing would be to bash the outside perhaps and break the ceramic, but if some parts are still to large to pass through the pipes that might be a bother?
I'll see if I can take it out first, it look tricky as there is a funny clamp that seems to need a specail tool???
Olivier

Alastair · #11 04-24-2010, 08:27 AM

Is the inlet to it also a right-angle bend...?

--so effectively its an 'S' shape-sorta...?

In which case it could be a bit of a pain....

Ones Ive done have all been inline with the cat, and easy to remove contents...

Olivier · #12 04-24-2010, 08:47 AM

Yes the inlet it worse, its at an angle and there is this S shape elbow to pass the steering colomn... No way from there.
Unfortunatly cutting it and re-weld it seems to be the "easiest" way

EdzBenz · #13 04-28-2010, 05:34 PM

I just jammed an old, thin file down the inlet of the pipe and broke all the stuff free. It takes a while, but its better than having to weld it back together. Just undo a few bolts, jam something in there to break it into pieces, and bolt it back up. Real easy project.

scottmcphee · #14 04-28-2010, 10:15 PM

Use a piece of flexible pipe for that section.

I replaced the cat with pipe on my 87 300D... a tiny bit louder at lower RPMs.