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De catting 318is

Posted: Thu Feb 12, 2009 9:51 am
by Weeman
Hi Guys, does anyone know what i need to do to de-cat my 1990 318 is. Its a euro car so has the cat and ideally I'd like to keep it for test purposes visually at least :) The cat is already empty, but makes a noise like a moped LOL Does anyone know If i can weld a pipe into the cat, or do I have to remove it completely and put either a flexi joint/pipe or straight piece of pipe on. I have no idea, so if anyone can help that would be great, thanks chaps :)

Re: De catting 318is

Posted: Thu Feb 12, 2009 9:59 am
by wrcarter
Would be easiest to remove it and weld in a bit of pipe instead

Re: De catting 318is

Posted: Thu Feb 12, 2009 10:22 am
by Weeman
Thought that might be the case, thanks

Re: De catting 318is

Posted: Wed Feb 18, 2009 5:08 pm
by A18RPF
By Euro do you mean UK or mainland Europe? Cos i have a 91 iS but was sure it didn't have a cat!

Re: De catting 318is

Posted: Wed Feb 18, 2009 5:19 pm
by Alex
before fitting my stainless steel exhaust i may decat mine, is it acutally worth it ??????

:D

Re: De catting 318is

Posted: Wed Feb 18, 2009 5:29 pm
by m666w
i think you might get a few more horses alex
you dont need a cat for mot if the car is pre 1992 .

Re: De catting 318is

Posted: Wed Feb 18, 2009 5:31 pm
by Alex
m666w wrote:i think you might get a few more horses alex
you dont need a cat for mot if the car is pre 1992 .
:cool: i thought it was 1991, i might just smash the internals out, same sort of thing, what happens with the lambda sensor or does that just stay as is

Re: De catting 318is

Posted: Wed Feb 18, 2009 5:32 pm
by DHFiS
Alex wrote:before fitting my stainless steel exhaust i may decat mine, is it acutally worth it ??????

:D
Are you sure it has one? There is a silencer that looks like a catalyst but there is no lambda sensor.

Re: De catting 318is

Posted: Wed Feb 18, 2009 5:34 pm
by Alex
DHFiS wrote:
Alex wrote:before fitting my stainless steel exhaust i may decat mine, is it acutally worth it ??????

:D
Are you sure it has one? There is a silencer that looks like a catalyst but there is no lambda sensor.
positive, ive checked the vin on that vin decoder thing on the net and it says its fitted with one, it also looks like it has one underneith, there is two boxes one must be the box you are on about and the other must be the cat

:D

Re: De catting 318is

Posted: Wed Feb 18, 2009 5:38 pm
by DHFiS
Alex wrote:
DHFiS wrote:
Alex wrote:before fitting my stainless steel exhaust i may decat mine, is it acutally worth it ??????

:D
Are you sure it has one? There is a silencer that looks like a catalyst but there is no lambda sensor.
positive, ive checked the vin on that vin decoder thing on the net and it says its fitted with one, it also looks like it has one underneith, there is two boxes one must be the box you are on about and the other must be the cat

:D
Fair enough. I'd remove it then, the ECU will still work without the input from the lambda.

Re: De catting 318is

Posted: Wed Feb 18, 2009 5:46 pm
by Alex
DHFiS wrote:
Alex wrote:
DHFiS wrote: Are you sure it has one? There is a silencer that looks like a catalyst but there is no lambda sensor.
positive, ive checked the vin on that vin decoder thing on the net and it says its fitted with one, it also looks like it has one underneith, there is two boxes one must be the box you are on about and the other must be the cat

:D
Fair enough. I'd remove it then, the ECU will still work without the input from the lambda.
:cool: thanks

Re: De catting 318is

Posted: Thu Feb 19, 2009 5:55 pm
by A18RPF
am I right in thinking that a CAT was an option on the iS?

Re: De catting 318is

Posted: Thu Feb 19, 2009 6:05 pm
by MrWhite
Must have been an option...

The spec sheet for my 318iS I got from Cotswold BMW shows that it was bought without a CAT. It has one now though. If a car that old doesn't require one by law why would it have been fitted?

Re: De catting 318is

Posted: Thu Feb 19, 2009 6:08 pm
by Alex
MrWhite wrote:Must have been an option...

The spec sheet for my 318iS I got from Cotswold BMW shows that it was bought without a CAT. It has one now though. If a car that old doesn't require one by law why would it have been fitted?
i got the spec sheet for mine and its a bum basic IS and never said it had a cat although it does

prehaps it could depend on the dealer or whoever was on the production line that day :mad: :mad:

Re: De catting 318is

Posted: Thu Feb 19, 2009 6:18 pm
by hoshy
Check that you've got a lambda sensor. An easy way it to look for a 4pin round connector under the battery tray. If that's got a blanking plug then it's got no lambda sensor, no lambda sensor == no cat. As said above the stock non-cat system has two boxes in the centre leading people to believe they have a cat when they don't.

Re: De catting 318is

Posted: Thu Feb 19, 2009 6:21 pm
by Alex
http://www.bmw-z1.com/VIN/VINdecode-e.cgi

that tells you weather you have a cat via the vin

mine does

Chassis number EE47738
Vehicle code AF92
Series E30
Model 318is
Body type coupe
Catalog model ECE
Production date 1990 / 09
Engine M42
Transmission Manual
Steering Right
Catalyzer YES

Re: De catting 318is

Posted: Thu Feb 19, 2009 6:23 pm
by magpie
so that's what that plug thing is.
cheers 8)

Re: De catting 318is

Posted: Thu Feb 19, 2009 6:25 pm
by MrWhite
hoshy wrote:Check that you've got a lambda sensor. An easy way it to look for a 4pin round connector under the battery tray. If that's got a blanking plug then it's got no lambda sensor, no lambda sensor == no cat. As said above the stock non-cat system has two boxes in the centre leading people to believe they have a cat when they don't.
There is now a massive hole under my battery tray where I attacked it with an air saw, don't remember seeing any connector. However, I put my VIN into the site mentioned above and it says it does have a CAT. (?)

Re: De catting 318is

Posted: Thu Feb 19, 2009 8:19 pm
by DHFiS
Alex wrote:http://www.bmw-z1.com/VIN/VINdecode-e.cgi

that tells you weather you have a cat via the vin

mine does

Chassis number EE47738
Vehicle code AF92
Series E30
Model 318is
Body type coupe
Catalog model ECE
Production date 1990 / 09
Engine M42
Transmission Manual
Steering Right
Catalyzer YES
Just checked mine and this website says catalyzerYES as well. Defo no lambda on mine though.