Removal of the Cat

[diversion74]

Read this with interest.
I can't afford the headers and after market exhaust at the moment and have wondered about the mod done on another thread where they remove the exhaust but leave the cat in place and just have a small ubend pipe.

Not sure whether this will damage the bike.

I only want a bit better sound.

Andy

 

[mark71]

Hi there Diversion this mod dosent change the sound of the bike at all just makes the bike a lot more responsive so good luck with your hunt.

Mark

 

[ktmmark]

No cat test for bikes of any year as yet & will no be retro dated .
As for the cat i have a spare set of 1200 pipes which i intend to knock the cat out & try,just not got round to it yet .
i intend to use a rod to so smash the catalist up (done this on cars many times when they get blocked) no need to cut open & weld

 

[Boxadog]

Well said Mark71

 

[BTBR]

Ok to all you nay sayers I have taken the cat out and tig welded it back up costing about oh let me think not including my labour about £1 including having the lights on in my workshop (posh word for garage) and wow what a difference it makes as became so apparant once I had cut open the pipes.

As the headers ar chrome I painted them in zinc paint and as it is all hidden up by the clamp anyway there isnt that much to see at all.

So to everyone who said dont bother I say why waste all the BMW r & d work that they carried out getting the headers just the right size and dimensions and just liberate it a bit oh and of course save a fortune.

And if I could work out how to post some pics I would not that I am thick or anything, guess I better pay my subscription again.

Well done for sticking with your idea, you are lucky to have both the tools and the skills in order to complete the job.

I too am more than capable of doing the same modification, however and just to add one very small detail here. Maybe when you come to sell the bike, it just "may" be a more attractive sale if it were reverted back to a standard bike.

Which of course it never can be unless you buy another std exhaust headers that still has the cat fitted.

Yes you will no doubt you will be able to buy a good second hand set, just like you can buy a good second hand set of Remus headers.

The very big plus side for the Remus headers are that they are a larger OD than the OE ones and the connecting pipe has been omitted. Together this all this adds to a vast improvement of both a much smoother power delivery and much better throttle response.

 

[deaninkl]

Hi Mark,

interesting thread, I live in Malaysia so don't need the cat for any legal reasons, can you tell me if removing it has any effect on the electronics set up? any need for re tuning etc, or is the CAN BUS able to cope with these changes?

 

[ktmmark]

Will have no affect to lambda as the o2 sensor's are pre cat only.
I think the the 1200 will respond well to this mod (will do it to mine soon)

 

[The Burpster]

Who let the cats out?

Mark.

The RSPCA arent going to be very happy with you keeping a cat in your exhaust all that time without milk and Whiskas....

Let the poor blighter out....! Cats should be running free in skips and on landfill sites and not in our choked restricted exhausts!

 

[(RIP) Arkwright]

And without the Cat.....

A 1200 without the the cat will do an average 7-8 miles per gallon better...............................................Polar ice caps and Chinese coal fired power stations being opened at 1-2 per week..........

Duncan

 

[Sgt Bilco]

Better fuel???

A 1200 without the the cat will do an average 7-8 miles per gallon better............................................ ...Polar ice caps and Chinese coal fired power stations being opened at 1-2 per week..........

Are you sure?? I have non standard headers (i.e no cat) and haven`t noticed better fuel consumption!! Makes the bike more responsive and sounds a load better though which is the desired effect.

 

[(RIP) Arkwright]

Non-cat Fuel consumtion

When my 1200GS was in standard form it did 50mpg for tank after tank, when I fitted the full Remus system without the cat at 2,300 miles the consumption improved to 57-58mpg and has stayed at this up to press, I have even had one of 60.7 on a long steady run! Current mileage 5450 (and no problems!)

Duncan

 

[Captain GSA]

Please take note- No cat, full remus system on my 12GSA. Mohamed who works at the exhaust fitters (West Africa's kwikfit) even put the bike down on it's side to show off his handy work. Nice job.

 

[Sgt Bilco]

Sit`s nicely on the pannier and cylinder head which is a nice touch

 

[ktmmark]

Ok had a look @ the spare exhaust & it's NOT a ceramic cat & will need to be cut out, so i will take it to work & cut it out & let you know how it goes.
This is one well made exhaust as you will find out if you try to remove your cat

 

[Captain GSA]

Sit`s nicely on the pannier and cylinder head which is a nice touch

Yes-If you buy the standard expandable GS panniers you could place a kit which contains BMW X5 air bags inside them. You then just get a remote activation control and with a press of a button the airbag explodes-inflates pushes the box out and the bike self rights! Simple solution to a back breaking problem. The kit is in prototype form and available from www.notsonippynorma.con

 

[litelfun]

OK Ive been thinking of cutting open the exhaust and removing the cat and then welding it back up again.

In theory it should flow a lot better but my question to all is has anyone done this mod before or know of any reason why I shouldnt attempt it.

Please answers on the back of a post card as usual and of course copious amounts of beer will be consumed before cutting commences always a good idea.

Hi I have removed the cat on two bickes GS1150 and HP2 much beter akustik you must diskonecht baterie to reset sensor 5min is ok have my original hp2 exhaust for sale if interested would licke 300 pound komplete

 

[zero 2]

Hi I have removed the cat on two bickes GS1150 and HP2 much beter akustik you must diskonecht baterie to reset sensor 5min is ok have my original hp2 exhaust for sale if interested would licke 300 pound komplete

Hi litelfun,

Can you explain how you removed the HP's cat? Do you still run the OE exhaust on the HP after the removal? And, do you have to disconnect the battery to reset the CO2 sensors.

 

[Ken H.]

Why do you want to pump more pollutants into the atmosphere? Any performance gain will be small. If you really want to go faster get a different bike or do an advanced rider course

Agreed

 

[Paul-K]

Cat Removal Pics

Ok to all you nay sayers I have taken the cat out and tig welded it back up costing about oh let me think not including my labour about £1 including having the lights on in my workshop (posh word for garage) and wow what a difference it makes as became so apparant once I had cut open the pipes.

As the headers ar chrome I painted them in zinc paint and as it is all hidden up by the clamp anyway there isnt that much to see at all.

So to everyone who said dont bother I say why waste all the BMW r & d work that they carried out getting the headers just the right size and dimensions and just liberate it a bit oh and of course save a fortune.

And if I could work out how to post some pics I would not that I am thick or anything, guess I better pay my subscription again.

Hi Mark,

I am assuming that you have a 1200GS cos the 1200GSA is different, so I am told. The CAT is built in the headers. Please post up some pics of the work that you did or send them to me if you wish and I can post them. [email protected] I have a 1200GSA and I would like a bike with no cat but the cost of the pipes put me off.

Cheers

Paul K

 

[EasySushi]

Hi Mark,

I am assuming that you have a 1200GS cos the 1200GSA is different, so I am told. The CAT is built in the headers. Please post up some pics of the work that you did or send them to me if you wish and I can post them. [email protected] I have a 1200GSA and I would like a bike with no cat but the cost of the pipes put me off.

Cheers

Paul K

Hi Paul,

I'm looking to do the same, I'm just down the road from you near Liphook,the 1200GSA exhaust is the same as the 1200.

Ty