cat needed?

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bobbin1982
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Post Sun May 20, 2018 7:20 pm

My L registration touring has a rotten centre box which im assuming is a cat
Do i need to replace with a cat or not?


Thanks
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Satan
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Post Sun May 20, 2018 10:40 pm

I think the cut off date was 1992 so K reg, not too sure though, Brianmoooore is the man with the knowledge so he should be able to help when he sobers up from celebrating the wedding......... ;o)))))
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Brianmoooore
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Post Sun May 20, 2018 10:44 pm

You need a cat. IF the car is fitted with a M40 (1.6 or 1.8) or a M20 (2.0 or 2.5) that was built after 08/'91 and it runs on petrol.
If your engine was built before this date, and you can prove it , or is any other type of engine, such as a M42 or a M5x, etc., or it runs on LPG, then you will be tested at MOT time to the pre 08/81 emissions regulations, and will not need a cat.
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Post Mon May 21, 2018 8:09 am

Brianmoooore wrote:You need a cat. IF the car is fitted with a M40 (1.6 or 1.8) or a M20 (2.0 or 2.5) that was built after 08/'91 and it runs on petrol.
If your engine was built before this date, and you can prove it , or is any other type of engine, such as a M42 or a M5x, etc., or it runs on LPG, then you will be tested at MOT time to the pre 08/81 emissions regulations, and will not need a cat.
Interesting Brian. I have an early E36 with M40 that was built in July 1991 but registered in August 91. It has the original cat. I wonder what it has been tested as?
bobbin1982
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Post Mon May 21, 2018 5:35 pm

cheers for the info guys
Looks like i need a cat... Need to source a second hand one in good nick if possible

Andrew
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Brianmoooore
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Post Mon May 21, 2018 7:38 pm

Unreadable engine number and details of an engine built earlier. You did replace your engine in the last year, didn't you?
bobbin1982
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Post Mon May 21, 2018 7:42 pm

If your asking me Brianmoooore No i havnt replaced my engine
As of yet anyway
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Brianmoooore
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Post Mon May 21, 2018 7:47 pm

bobbin1982 wrote:If your asking me Brianmoooore No i havnt replaced my engine
As of yet anyway
Well now would be a could time, even if you replace it with exactly the same engine!
Read between the lines - there are ways around this problem.
Whatever you do, don't get a MOT fail recorded for not having a cat.
bobbin1982
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Post Mon May 21, 2018 9:22 pm

ok so what im thinking is somehow convince them my engine is earlier am i right?... then getting myself a downpipe from a non cat car?

Is there any more information how to accomplish this?


Andrew
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bobbin1982
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Post Mon May 21, 2018 9:49 pm

https://www.ebay.co.uk/itm/Front-Exhaus ... SwLehazw-9

TBH this is the best price i have had..

2 other prices i had were £160 and £200 and apparently they were both already tweaked when i asked is that the best you can do
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Brianmoooore
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Post Mon May 21, 2018 11:01 pm

bobbin1982 wrote:ok so what im thinking is somehow convince them my engine is earlier am i right?... then getting myself a downpipe from a non cat car?

Is there any more information how to accomplish this?


Andrew
I've already mentioned one thing, and their are minor differences between some of the ancillaries between late and early M40 engines. One of these would be an AFM with a CO adjustment pot. in the side of it. You would need this anyway to adjust CO, unless you modified the non cat. exhaust to take your existing lambda sensor.
I see that cat. exhausts are available at a reasonable price, and while cats. don't seem to hurt the power output on M40 engines, they do badly affect the fuel consumption.
bobbin1982
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Post Tue May 22, 2018 8:35 pm

Sorry i must sound thick
Ill try and find more information on this subject
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bobbin1982
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Post Tue May 22, 2018 10:40 pm

so if i cut out the cat and and welded in a piece of pipe to rejoin the exhaust would the lambda be ok to leave in and will it work properly without a replacement afm or is the new afm still needed?

Ill explain to the M.O.T tester that i had my new engine fitted from a 1990 car but lost the paper work in my house move ( silly me )and ask if he will be willing to do a pre 1992 test before i book a slot
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Brianmoooore
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Post Tue May 22, 2018 11:49 pm

A lambda sensor will work with an AFM that does not have a CO pot.
bobbin1982
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Post Wed May 23, 2018 7:21 pm

Cheers Brianmoooore i was slow to catch on but i got there :roll:
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