Catalytic

MHOLST

New member
Points
21
From
Oslo Norway
Car
e320 avantgarde
Hi Guys
I just have a question om my MB e320 w210 i got 2 cats (straight engine not the V6) and am planing to get a sports cat ( am gona replace the whole exhaust) is it ok just to use one cat. the cats thats on the car now sits beside each other.
Whould be happy for reply on this :)
 

obi_waynne

Administrator
Staff member
Moderator
Points
1,137
From
Deal, Kent UK
Car
A3 1.4 TFSI 150 COD
You can only really go down to one cat if the entire exhaust stream flows through it. So if it splits before the cat you will need two but if you can split the exhaust after the catalyst you should be ok with one but you'll need a bigger catalyst as you are going from two down to one.
 

MHOLST

New member
Points
21
From
Oslo Norway
Car
e320 avantgarde
You can only really go down to one cat if the entire exhaust stream flows through it. So if it splits before the cat you will need two but if you can split the exhaust after the catalyst you should be ok with one but you'll need a bigger catalyst as you are going from two down to one.

Hi Wayne
Many thanks for your reply ( i tryed to add a photo of the exhaut but it didnt work)

There is one pipe from each headers that goes in to one pipe and this pipe splits for the two cats and there is one pipe after each cat that goes into the muffler .From the muffler and out there is only one pipe that goes to the backbox.
I was thinking of using a bigger cat and bigger pipe (3 inch) all the way between the muffler and backbox .Am gonna change the muffler and backbox to.
 

obi_waynne

Administrator
Staff member
Moderator
Points
1,137
From
Deal, Kent UK
Car
A3 1.4 TFSI 150 COD
Just make sure the surface area of the catalyst is the same as that of the original cats to maintain the flow rate, and try not to introduce any sharp bends in ether pipe work.
 

MHOLST

New member
Points
21
From
Oslo Norway
Car
e320 avantgarde
Just make sure the surface area of the catalyst is the same as that of the original cats to maintain the flow rate, and try not to introduce any sharp bends in ether pipe work.
The pipe that goes into each cat are 2 inch
 
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Charliep

Torque Junkie
Points
22
From
Thurrock, UK
Car
Alfa GTV & 33
The reason for the 2 cats is emission regulation requirements and the need to run 2 pipes (secondary length) for exhaust calculation reasons.

Depending on the regulation in different countries in Europe it might be a problem to bring the cat too far away from the engine.
 

MHOLST

New member
Points
21
From
Oslo Norway
Car
e320 avantgarde
The reason for the 2 cats is emission regulation requirements and the need to run 2 pipes (secondary length) for exhaust calculation reasons.

Depending on the regulation in different countries in Europe it might be a problem to bring the cat too far away from the engine.

so i guess its best to go for two cats then.
How do i add photos here ??
 

pgarner

TC ModFather
Points
417
From
Lockerbie, SW Scotland
Car
Octy smoke machine
you need 10 posts - give it a while for the forum to notice and your name will turn bold.
host the pictures on the likes of photobucket and paste the IMG code.


(can take around 1/2 hr for the forum to refresh the users after you make the 10 posts as soon as you see your name in bolt youll have the ability to post pics, link and use PMs - please dont post links that may be seen as advertising or competing sites )
PGarner
 

MHOLST

New member
Points
21
From
Oslo Norway
Car
e320 avantgarde
you need 10 posts - give it a while for the forum to notice and your name will turn bold.
host the pictures on the likes of photobucket and paste the IMG code.


(can take around 1/2 hr for the forum to refresh the users after you make the 10 posts as soon as you see your name in bolt youll have the ability to post pics, link and use PMs - please dont post links that may be seen as advertising or competing sites )
PGarner
Many thanks for the info :)
 

MHOLST

New member
Points
21
From
Oslo Norway
Car
e320 avantgarde
Yes, and make a boss for post lambdas. The cats do not need to sit exactly side by side if it is a space issue.

Its only one Lambda on the exhaust it sits in the Y-split just infront of the cats. its plenty of space for two cats
 
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