240 General: - Cat fitment?

minesa240x3 · Jan 4th, 2013, 00:04

Hi folks this will only apply to those of you unfortunate enough to have a catalytic converter fitted.I have a K reg which unfortuneately "HAS" to have one fitted for emmissions.I was wondering if anyone has ever had the FLAT flange fitment with gasket?I was going to get a new cat tomorrow but cannot remember which fitting mine has.I think it may well be the male flared flange type which has a steel ring between the cat and middle pipe.
I am aware that suppliers ask which type you need as both are available.

Regards Brian.

Clifford Pope · Jan 4th, 2013, 08:05

It's the front fitting that varies. The exit is just a long section of pipe that sleeves into the centre silencer in the usual way.

My K-reg, and J, have the front fitting with a loose ring with 3 holes on the cat pipe, bolting onto a fixed flange on the end of the down pipe.
There is conical section sealing ring sandwiched in between (no gasket).

Does the sensor screw into the cat on yours ? There is a variant where the sensor screws into the down pipe a few inches forward of the cat, and another that screws into the exhaust manifold.

wooble · Jan 4th, 2013, 11:40

My '93 has the conical flange/sealing ring arrangement and the 02 sensor just forward of the cat.

Volvorama · Jan 4th, 2013, 13:39

For some markets the cat is fitted in a different place. Very appropriate for the season - name that Panto!

minesa240x3 · Jan 4th, 2013, 17:18

Looks like puss in boots Lol.
Thanks guys I didn't go buying the cat today but will have another look to see if the lambda probe hole is on the down pipe.
I got the car minus the exhaust,So no cat or pipework beyond that.I will have to have a look at my J reg too to see where the lambda screws into?

I seem to remember seeing the flared flange but being it was so long ago I wasn't sure.Especially after researching and constantly seeing two types listed.

I really just want to get the car running so I can move it about to work on.It's a wee bit loud especially as it won't tickover.You have to blip the throttle and keep doing this just to get it revving high enough to move.

Funny old thing as it always fires up on the first turn of the key.In fact every time it's turned it fires revs and then stops.

Cheers guys,Brian.

minesa240x3 · Jan 4th, 2013, 17:22

Just to say if it was a J reg I would leave the cat off and get a threaded spigot welded to the front down pipe.I had to do this to my 740 as it had no cat and the lambda probe was not connected.
Sorted out the running issues.
Regards Brian.

Clifford Pope · Jan 4th, 2013, 20:02

I've sometimes thought about removing the cat on mine (June 92), but as I happened to have an entire stainless steel exhaust from another car it was easier to fit that when the cat collapsed.

What do you use instead of the cat - get a longer downpipe for one of the earlier carburetor models, which connects straight to the middle silencer?

BTW I don't think you can do that with all J-reg, it depends on the month in 1992. The cut-off date for the earlier emissions test is July, AFAIK?

It makes an enormous difference to the ease of passing MOT tests. The cat test is quite rigorous, and a car that is running really well can still fail on marginal lambda and NOX readings. But a pre-July 92 car only has to pass the old carburettor CO limit, which is easy.

minesa240x3 · Jan 4th, 2013, 20:54

Hi there I just revisited my old post in the wanted section.27-1-2011.
Yes you are correct about the date but to be more specific the legislation states that on or before this date you will not need a catalytic converter fitted for test 3-7-1992.(Unless it was fitted from original,Just deny it)
So if your car was registered before this date it could have the cat removed.
My J reg is 17-7-1992 so fourteendays before the legislation came in.

The K reg was registered 23-4-1993 so will have to be tested according to new legislation.

My 740 had no cat and I don't think the previouse owner knew it.He had a new exhaust fitted and remarked on how cheap it was.Shame they didn't tell him about unplugging the lambda probe.

Apparently if you just leave the probe connected but dangling down it will affect running but if you disconnect it the car will run in default mode,Not great.

I can't remember what thread it had to be but it may be sparg plug thread size?
The guy who did mine cut the boss off of an old cat he had laying about,cut a small hole in the downpipe and brazed it in..

Regards Brian.

tannachyallen · Jan 4th, 2013, 22:05

Hi Brian,
my J reg was registered in 91 but it had a cat as original equipment.

I have changed all my exhaust to a SS, single (rear) silencer, bigger bore system for better MPG. It has passed the last 3 MOTs fine.

The lambda must be connected as its part of the fuel mixture system, at least on injection models.

It may look as if it's in the cat, but it's actually taking readings from gasses just before they get to the cat. So if your car is registered for the pre-cat test you could get shot of it. (the cat that is, not the lambda

)

Dave A.

minesa240x3 · Jan 4th, 2013, 22:14

Thanks so are you saying the hole for the Lambda probe is part of the front casing of the cat? Or in the downpipe?
I seem to remember a much smaller bolt in the front downpipe?Unless that was on the 740?
Regards Brian.

Jan 4th, 2013, 00:04	#1
minesa240x3 loyalty Last Online: Jul 28th, 2022 19:16 Join Date: May 2006 Location: faraway View Photos By: minesa240x3	Cat fitment? Hi folks this will only apply to those of you unfortunate enough to have a catalytic converter fitted.I have a K reg which unfortuneately "HAS" to have one fitted for emmissions.I was wondering if anyone has ever had the FLAT flange fitment with gasket?I was going to get a new cat tomorrow but cannot remember which fitting mine has.I think it may well be the male flared flange type which has a steel ring between the cat and middle pipe. I am aware that suppliers ask which type you need as both are available. Regards Brian.

Jan 4th, 2013, 11:40	#3
wooble Stay gold baby! Last Online: Jul 24th, 2022 16:15 Join Date: May 2009 Location: Bristol	My '93 has the conical flange/sealing ring arrangement and the 02 sensor just forward of the cat. __________________ Click to see 240 parts I want to give you money for!

Jan 4th, 2013, 22:05	#9
tannachyallen 240SE Last Online: Mar 4th, 2019 20:44 Join Date: May 2007 Location: Strath Brora	Hi Brian, my J reg was registered in 91 but it had a cat as original equipment. I have changed all my exhaust to a SS, single (rear) silencer, bigger bore system for better MPG. It has passed the last 3 MOTs fine. The lambda must be connected as its part of the fuel mixture system, at least on injection models. It may look as if it's in the cat, but it's actually taking readings from gasses just before they get to the cat. So if your car is registered for the pre-cat test you could get shot of it. (the cat that is, not the lambda ) Dave A. __________________ 240 SE Auto 1991 Last edited by tannachyallen; Jan 4th, 2013 at 22:10.

Jan 4th, 2013, 08:05	#2
Clifford Pope Not an expert but ... Last Online: May 9th, 2024 08:24 Join Date: Dec 2001 Location: Boncath	It's the front fitting that varies. The exit is just a long section of pipe that sleeves into the centre silencer in the usual way. My K-reg, and J, have the front fitting with a loose ring with 3 holes on the cat pipe, bolting onto a fixed flange on the end of the down pipe. There is conical section sealing ring sandwiched in between (no gasket). Does the sensor screw into the cat on yours ? There is a variant where the sensor screws into the down pipe a few inches forward of the cat, and another that screws into the exhaust manifold.

Jan 4th, 2013, 17:18	#5
minesa240x3 loyalty Last Online: Jul 28th, 2022 19:16 Join Date: May 2006 Location: faraway View Photos By: minesa240x3	Looks like puss in boots Lol. Thanks guys I didn't go buying the cat today but will have another look to see if the lambda probe hole is on the down pipe. I got the car minus the exhaust,So no cat or pipework beyond that.I will have to have a look at my J reg too to see where the lambda screws into? I seem to remember seeing the flared flange but being it was so long ago I wasn't sure.Especially after researching and constantly seeing two types listed. I really just want to get the car running so I can move it about to work on.It's a wee bit loud especially as it won't tickover.You have to blip the throttle and keep doing this just to get it revving high enough to move. Funny old thing as it always fires up on the first turn of the key.In fact every time it's turned it fires revs and then stops. Cheers guys,Brian.

Jan 4th, 2013, 17:22	#6
minesa240x3 loyalty Last Online: Jul 28th, 2022 19:16 Join Date: May 2006 Location: faraway View Photos By: minesa240x3	Just to say if it was a J reg I would leave the cat off and get a threaded spigot welded to the front down pipe.I had to do this to my 740 as it had no cat and the lambda probe was not connected. Sorted out the running issues. Regards Brian.

Jan 4th, 2013, 20:02	#7
Clifford Pope Not an expert but ... Last Online: May 9th, 2024 08:24 Join Date: Dec 2001 Location: Boncath	I've sometimes thought about removing the cat on mine (June 92), but as I happened to have an entire stainless steel exhaust from another car it was easier to fit that when the cat collapsed. What do you use instead of the cat - get a longer downpipe for one of the earlier carburetor models, which connects straight to the middle silencer? BTW I don't think you can do that with all J-reg, it depends on the month in 1992. The cut-off date for the earlier emissions test is July, AFAIK? It makes an enormous difference to the ease of passing MOT tests. The cat test is quite rigorous, and a car that is running really well can still fail on marginal lambda and NOX readings. But a pre-July 92 car only has to pass the old carburettor CO limit, which is easy.

Jan 4th, 2013, 20:54	#8
minesa240x3 loyalty Last Online: Jul 28th, 2022 19:16 Join Date: May 2006 Location: faraway View Photos By: minesa240x3	Hi there I just revisited my old post in the wanted section.27-1-2011. Yes you are correct about the date but to be more specific the legislation states that on or before this date you will not need a catalytic converter fitted for test 3-7-1992.(Unless it was fitted from original,Just deny it) So if your car was registered before this date it could have the cat removed. My J reg is 17-7-1992 so fourteendays before the legislation came in. The K reg was registered 23-4-1993 so will have to be tested according to new legislation. My 740 had no cat and I don't think the previouse owner knew it.He had a new exhaust fitted and remarked on how cheap it was.Shame they didn't tell him about unplugging the lambda probe. Apparently if you just leave the probe connected but dangling down it will affect running but if you disconnect it the car will run in default mode,Not great. I can't remember what thread it had to be but it may be sparg plug thread size? The guy who did mine cut the boss off of an old cat he had laying about,cut a small hole in the downpipe and brazed it in.. Regards Brian.

Jan 4th, 2013, 22:14	#10
minesa240x3 loyalty Last Online: Jul 28th, 2022 19:16 Join Date: May 2006 Location: faraway View Photos By: minesa240x3	Thanks so are you saying the hole for the Lambda probe is part of the front casing of the cat? Or in the downpipe? I seem to remember a much smaller bolt in the front downpipe?Unless that was on the 740? Regards Brian.

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