MR2 Roadster Owners Club

The Workshop => Maintenance, Problems & Troubleshooting => Topic started by: Peter Wright on September 7, 2004, 15:54

Title: Decat manifold on e-bay
Post by: Peter Wright on September 7, 2004, 15:54
 m http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... 62717&rd=1 (http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&category=10428&item=2489162717&rd=1) m
But it says it will not pass the MOT test ???
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Post by: Anonymous on September 7, 2004, 15:58
As far as i'm aware having no cat at all will fail the test.  Removing the pre-cats wont affect this because they're mainly for warm up use anyway.

This system is a cat replacement (kinda) as so is for track use only.

am i right?
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Post by: Peter Wright on September 7, 2004, 16:03
Quote from: "odub"As far as i'm aware having no cat at all will fail the test.  Removing the pre-cats wont affect this because they're mainly for warm up use anyway.

This system is a cat replacement (kinda) as so is for track use only.

am i right?

Good job I aint got my gutting screwdriver out yet init as these are what I was going to gut

  s:? :? s:?    s:? :? s:?
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Post by: mph on September 7, 2004, 16:09
Quote from: "odub"As far as i'm aware having no cat at all will fail the test.  Removing the pre-cats wont affect this because they're mainly for warm up use anyway.

This system is a cat replacement (kinda) as so is for track use only.

am i right?
No.

You *can* get the '2 through without any CATs, but you'll need something to tweak the fueling with - ie a Unichip, eManage or PowerFC et al.
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Post by: aaronjb on September 7, 2004, 16:11
Quote from: "odub"As far as i'm aware having no cat at all will fail the test.  Removing the pre-cats wont affect this because they're mainly for warm up use anyway.

You were right with that bit  s:) :) s:)

That ebay ad is *only* for the exhaust manifold - which is where the pre cats live. Peter - you can gut these at will  s;) ;) s;)  and still pass an MOT with flying colours (so that advert is a bit wrong).

The main CAT is the one you can't lose - that's the large canister that is a sort of U shape - bolts to the bottom of the exhaust manifold (the ebay item), goes down a bit then across (from right to left I think) and gets larger (where the main CAT itself lives) then goes back upward into the exhaust box..

Anyway, as I say - you can fit that manifold and/or gut your pre CATs (which live in the manifold shown) and still pass an MOT.

Gut the main CAT and you'll fail (unless you do supporting work), plus lose bags of bottom end torque..

[edit] And Martin beat me to it with a much more succinct post  s:) :) s:)
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Post by: SteveJ on September 7, 2004, 16:24
If you remove the main cat, technically you will fail as the test sheet includes a visual inspection of the CAT to ensure it is present. Most MOT testers dont really care as long as they get the print out from their gas sniffer that shows the emissions are OK.
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Post by: Tem on September 7, 2004, 20:56
Quote from: "SteveJ"If you remove the main cat, technically you will fail as the test sheet includes a visual inspection of the CAT to ensure it is present. Most MOT testers dont really care as long as they get the print out from their gas sniffer that shows the emissions are OK.

I wonder if this works in the UK as well...I assume it should. Just replace the cat with a straight pipe and put the covers on it. You can't really tell the difference without taking the covers off...

The values will be a lot worse without any cat though, even if they are still within the limits. The inspector should notice it...but over here they really don't care, sometimes you just get some "your cat doesn't seem to be working properly, would be a good thing to change it" or whatever  s:roll: :roll: s:roll:
Title: Decat manifold on e-bay
Post by: spit on September 28, 2004, 16:42
Hope the de-pre-catted manifold works at MOT - I'm the chump who bought the thing off Ebay! Still, always got the original to hoik back on just in case.
  s:oops: :oops: s:oops:  
I found a post elsewhere (& then lost it) about the merits of fitting a new manifold gasket. I know some people get away with it but I've never had any luck with re-using these bits in the past, so figure its worth the investment....
The other post seems to quote a part number for a pipe gasket - entirely different beast - so for those of you who are shopping at Mr. T's, the correct part number for the manifold gasket is T17173-22010
(price £9.86 + vodka-and-tonic).
Just gotta get a decent 02 sensor socket, lube up the studs, paint the heatshield (thanks for the inspiring article Markiii),  and its all systems go.
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Post by: Anonymous on September 29, 2004, 12:36
For the emissions test (on recent cars), do they not have to plug something on the diagnostics socket to measure what the O2 sensors are reporting?

They do that now over here so without the main cat, you have no chance in hell of passing. However a '2 without the warm-up pre-cats will still pass the test as the engine must be warmed up first before the test starts...
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Post by: Tem on September 29, 2004, 12:43
Quote from: "phat"For the emissions test (on recent cars), do they not have to plug something on the diagnostics socket to measure what the O2 sensors are reporting?

They do that now over here so without the main cat, you have no chance in hell of passing.

If they are measuring the 3rd O2 sensor...wouldn't an O2 condinioner keep the tester happy? Just like it keeps the stock ECU happy?
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Post by: Anonymous on September 29, 2004, 12:56
The tests are carried out by ordinary garages... It's only the machine that dictates, so there's room to manoeuvre. You could probably trick them as long as they don't think you will get stopped by the police... because if you get caught by the authorities, I heard the fines are pretty massive (for the car owner and the garage that did the "dud" test).

What many people do, is (like with "tuned" motorbikes): you just borrow/swap the standard equipment just to pass the tests (some garages will even lend you the stuff)...   s:) :) s:)
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Post by: Anonymous on September 29, 2004, 17:25
I'm with spit, here (my, doesn't that sound odd?). Got the heat shield off already and am currently painting it (same color as mark's). Ordered a new gasket and "doughnut" rings. Y'know, considering the labor and, in my case, expenditure for tools and whatnot, new gaskets cost practically nothing and I can't understand why anyone would be parsimonious at that point of the procedure.
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Post by: Anonymous on September 29, 2004, 21:54
In general - another choice would be:

(http://www.my-mr2.de/albums/albun95/TRD_Kr_mmer.jpg)

the TRD header....at least in Germany it made it through the emissions test   s:wink: :wink: s:wink:  
(can be ordered in the US - send me a PM if you need the contact name)