My Show and Tell - Catalytic Convertor Removal.

TaKeN

TaKeN

TaKeN

Soldato
Joined
18 Aug 2005
Posts
13,188
Location
Shropshire
Evening All,

Yesterday I decided to attack the my 306 HDi, with the intention of removing the cat,

Firstly I jacked the car up on one side with two jacks and a massive piece of wood under the car just incase the jacks failed.

I got all my tools and scrambled under the beasty.. Only to get a bit confused as to how the Front Pipe came off, I knew how to remove the exhaust clamps but had never removed anything from the front section of an exhaust before... Fortunately one of the mechanics off 306.net was on MSN and guided me through the process ( Dead Easy )

Exhaust is back on the car now and I find it is a lot more responsive and nicer to drive..

Pics below for you all to enjoy :D

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Above You can see my exhaust section, I welded a Brace onto the pipe so that the exhaust would stay the same shape as before and not cause me problems when refitted.

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Above is a close up of the cat I set out to remove,

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Above, The attack was complete. One nasty cat removed :D

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Above, New piece of pipe welded in place, Fortunately my dads friend is a Mechanic so I drove down the road and he let me have a piece out of his scrap pile.

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Above, Close up shot of the welds.. Not the best in the world but I ground them down and welded over them again on a hotter heat just to be sure that there was a proper seal.

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Above, Finally the exhaust was ready to refit.. I thought.. Until I remembered that Black gloss paint will probably melt once it gets hot.. So Before I went to bed I removed all the black paint and put some " Galvafroid " on to keep the rust away :D

Now before anyone shouts " Oi that won't pass its MOT " I've been told by many people with this Done that It does pass and MOT because they test the emissions, and the Cat on this car does sod all.. ( Legal on Some Diesels ? Illegal on Petrols )

EDIT - Pics Rehosted due to imageshack taking ages to load

John.
 
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ScoobyDoo69 said:
Any difference in performance? Decatting the scoob made a nice difference, how does it on a HDi?
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I took it for a drive today, It felt a lot more responsive ( Quicker to rev ) and generally nicer to drive.

From what I've read on forums it releases about 2-3 HP and allows the turbo to spool up quicker, Not much of a gain but its alright for free :D

Matt82 said:
nice, like the way you did it yourself, clever way of linking original pipework etc

well done
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Thanks, I enjoyed doing it to be honest and wanted to try and make it look as original as possible :)
 
good for you :)

nice to see a fellow ocuker who's into diy exhausts :)

reminds me of fitting straight thru side exits to rusty cavaliers
 
Tim said:
While I've got a de-cat fitted, i'm not sure i'd de-cat a 306 diesel :o
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Its a restriction which isn't needed so removing its all good :) I know it doesn't release any huge amounts of power but I think its worth it.


Foxtrot26 said:
good for you :)

nice to see a fellow ocuker who's into diy exhausts :)

reminds me of fitting straight thru side exits to rusty cavaliers
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I love messing around with the welder and grinder, I live on a farm so thats why the workshop looks a mess :p

Got lots of big grinders, lovely gas MIG welder, Band Saw ( Metal Cutting ) + other goody's :D
 
TaKeN said:
I took it for a drive today, It felt a lot more responsive ( Quicker to rev ) and generally nicer to drive.

From what I've read on forums it releases about 2-3 HP and allows the turbo to spool up quicker, Not much of a gain but its alright for free :D



Thanks, I enjoyed doing it to be honest and wanted to try and make it look as original as possible :)
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:D
 
New exhaust and decat turning up on friday. Sadly I didn't make it myself so I definatly lose manly points :(
 
6thElement said:
Placebo picture :D
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One member over at 306.net net claims it gave 3hp over stock and a bit more torque on the dyno so :p

Also, I will take a picture for you tommorow to show you just how restrictive the cat is, You look down it and there is a tiny pinprick hole at the other end :o
 
As Promised.. Some rubbish pics of the cat from the End showing how restrictive it is..

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That realy is a tiny hole you can see down the end, but there is very very fine mesh all through the cat, I think this gets blocked with soot over time aswell.
 
The cat fitted on the XUD engines removes about 10hp according to the figures so as long as it'll pass an mot it's got to be worth it. Maybe less so on the HDi as i would guess it's been designed with CATs and EGR valves in mind rather than having htem fitted as a green afterthought.
 
The Edge said:
The cat fitted on the XUD engines removes about 10hp according to the figures so as long as it'll pass an mot it's got to be worth it. Maybe less so on the HDi as i would guess it's been designed with CATs and EGR valves in mind rather than having htem fitted as a green afterthought.
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I've already unplugged the EGR Valve aswell btw :)
 
Disconnect the wire on top of the fuel pump aswell, think it was a orange clip on both my HDis. You might notice alittle more 'pull' low down.
 
Matt82 said:
id take the egr out first, clean it up to make sure its actually closing fully

yours vac operated on that engine?
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I'm not too sure matt, I've pulled the blue power connector out of the back of it to stop the solenoid from opening, But like you say it might be stuck open due to all the crud that runs through it.

Atom said:
Disconnect the wire on top of the fuel pump aswell, think it was a orange clip on both my HDis. You might notice alittle more 'pull' low down.
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I will give this a try later, Ta.
 
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