De catting Griff 500
Discussion
Any help would be much appreciated. After looking into this I have decided to take out the pre cats and may be changing the manifolds for better ones. Can anyone tell me the following
1) Situation with MOT
2) Do I still need the lambda sensors or not
3) Cost?
4) Does the ECU need to be touched? if yes any idea where I can get the software from for re mapping
5) Any idea for the values of the resistor to help the ECU?
6) Any other ideas or suggestions.
The car is a 1994 500, pre serp, with pas and ac
Thanks
Nad
1) Situation with MOT
2) Do I still need the lambda sensors or not
3) Cost?
4) Does the ECU need to be touched? if yes any idea where I can get the software from for re mapping
5) Any idea for the values of the resistor to help the ECU?
6) Any other ideas or suggestions.
The car is a 1994 500, pre serp, with pas and ac
Thanks
Nad
Edited by Mad Nad on Friday 27th April 13:40
I see you're from Hampshire, like me.
I took my Griff to Fernies and got a sports exhaust for £250! Sounds great and they MOT'd it so it passed that okay! I wouldn't say it feels any quicker, but it's quick enough anyway. I have to say though, the noise is 10 times better. It even pops like an F1 car on occasional down shifts!
I took my Griff to Fernies and got a sports exhaust for £250! Sounds great and they MOT'd it so it passed that okay! I wouldn't say it feels any quicker, but it's quick enough anyway. I have to say though, the noise is 10 times better. It even pops like an F1 car on occasional down shifts!
1. No problem - just dont expect to pass emissions until car is warmed up - most of us just give it a good thrash before going to MOT.
2. Yes - you still have main cat.
3. You can do it for nothing if you just chisel the pre-cats out, but I would take manifolds off personally and allow for cost of gaskets & maybe some paint....
4. No change.
5. Dont need to consider changing unless you remove main cat.
The pre-cats are in the manifolds, the main-cat is in the y-piece/dustbin at the front. The main cat is sufficient to pass MOT enissions tests, the pre-cats only assist before the main-cat is up to temperature (which is a manufacturers conformance test - not applicable to Joe Public). If you start considering changing the manifolds that can start becoming quite expensive (they used to be over £600 IIRC).
Dave
2. Yes - you still have main cat.
3. You can do it for nothing if you just chisel the pre-cats out, but I would take manifolds off personally and allow for cost of gaskets & maybe some paint....
4. No change.
5. Dont need to consider changing unless you remove main cat.
The pre-cats are in the manifolds, the main-cat is in the y-piece/dustbin at the front. The main cat is sufficient to pass MOT enissions tests, the pre-cats only assist before the main-cat is up to temperature (which is a manufacturers conformance test - not applicable to Joe Public). If you start considering changing the manifolds that can start becoming quite expensive (they used to be over £600 IIRC).
Dave
Quinny said:
Depending on when your car was registered, dictates the MOT emisions standard it must meet.
As an example, my car failed the cat test yesterday (precats removed but main cat still in place) . But as it was registered before 31/7/94 This was the wrong test.
When it was tested as though it didn't have a cat, it passed easily.
The earlier test says this
CO Max 3.5% Mine was 0.30%
HC Max 1200ppm Mine was 280ppm
This website explains it in more detail. But the point is make sure you get the right test for the age of your car.
www.bobmckay.co.uk/p_emissions.html
As an example, my car failed the cat test yesterday (precats removed but main cat still in place) . But as it was registered before 31/7/94 This was the wrong test.
When it was tested as though it didn't have a cat, it passed easily.
The earlier test says this
CO Max 3.5% Mine was 0.30%
HC Max 1200ppm Mine was 280ppm
This website explains it in more detail. But the point is make sure you get the right test for the age of your car.
www.bobmckay.co.uk/p_emissions.html
Hi,
Thanks for this and good point too. Mine is registered 22.06.1994. So it should pass without the pre cats as yours did, should they do the correct test?
Nad
Quinny said:
CO Max 3.5% Mine was 0.30%
HC Max 1200ppm Mine was 280ppm
HC Max 1200ppm Mine was 280ppm
Those tests are for cars before 1992 are they not? 92-94 are a little more stringent. AFIK removal of the pre-cats in the manifolds does not mean post 94 cars will fail emissions. It is also possible if your cat is foobarred it may fail any test....
I think some of these posts could be getting very confusing....
Dave
spend said:
Quinny said:
CO Max 3.5% Mine was 0.30%
HC Max 1200ppm Mine was 280ppm
HC Max 1200ppm Mine was 280ppm
Those tests are for cars before 1992 are they not? 92-94 are a little more stringent. AFIK removal of the pre-cats in the manifolds does not mean post 94 cars will fail emissions. It is also possible if your cat is foobarred it may fail any test....
I think some of these posts could be getting very confusing....
Dave
Wot E Sed
Has he got a "Vehicles with 6 or more seats are not passenger cars and are subject to less stringent requirements usually:" or does'nt read he his own damn links before being @rsey about other folks actually reading them carefully!
Dave
Dave
Nice to see you - just for a moment PH
Edited by spend on Saturday 28th April 20:47
Not sure what you're getting at. The fact that the 2 references you have supplied use conflicting data does'nt seem to me to be very helpful, although I would rather believe that later one. I'm sorry but I didnt see how it contributed, still think the first link you posted was incorrect in its wording/layout.
So to recap what you are trying to say for TVR's is:
Put on the road 1/8/92-31/7/95 = CO<=3.5% HC<=1200ppm (nonCAT test)
Put on the raod 1/8/95-31/8/02 = CO<=0.3% HC<=200ppm ...(CAT test)
Is that correct?
Dave
PS. I still have never heard anyone else say that removal of the precats will adversely affect emissions when the cat is up to temp.
So to recap what you are trying to say for TVR's is:
Put on the road 1/8/92-31/7/95 = CO<=3.5% HC<=1200ppm (nonCAT test)
Put on the raod 1/8/95-31/8/02 = CO<=0.3% HC<=200ppm ...(CAT test)
Is that correct?
Dave
PS. I still have never heard anyone else say that removal of the precats will adversely affect emissions when the cat is up to temp.
OK as a full & final comment...
The verbose extract of your first link:
Passenger cars:
* First used before 1/8/1975 - Visual test only. Failure for excess idle speed, dense blue or black smoke for 5 seconds at idle or during acceleration up to 2500rpm or half engine max speed whichever lowest.
* First used between 1/8/75 and 31/7/86 - meter test CO <=4.5%, HC<=1200ppm.
* First used between 1/8/86 and 31/7/92 - meter test CO<=3.5%, HC<=1200ppm.
* First used between 1/8/92 and 31/7/94 - advanced emission test (CAT) if its running on petrol when presented, to the vehicle specific limits usually around CO<=0.3%, HC<=200ppm and Lambda 0.97 - 1.03. Remember from 1st August 2001 a basic emission test will be carried out initially.
Note that the tests vehicles for first registered on or after 1/8/92 require expensive exhaust gas analyser equipment which is usually only available to the trade. However, there is DIY equipment available which is relatively inexpensive to enable emissions tests on vehicles prior to that date.
Vehicles with 6 or more seats are not passenger cars and are subject to less stringent requirements usually:
* Registered between 1/8/92 and 31/7/94 - meter test CO<=3.5% HC<=1200ppm
* Registered on or after 1/8/94 and an exact match can be found in the DTP data book or analyser database then CAT test to specified limits otherwise CO<=3.5% HC<=1200ppm
Which to me implied that highlighted part all (& only) applied cars with >=6 seats
You seemed to be wishing to quote the first highlighted rule as being applicable to you. This quite naturally confused the poo out of me, so I pointed it out (only to be told I had'nt been @rsed to read it?).
Then you go on to quote a VOSA document. If you actually read the 2 test criteria you've referenced they are different. Does that not raise some concerns? Are they just plain wrong, superceded, or plain out of date? - I think that is a classic case of causing confusion!
Now Vosa seems to state:
Put on the road 1/8/92-31/7/95 = CO<=3.5% HC<=1200ppm (nonCAT test)
Put on the road 1/8/95-31/8/02 = CO<=0.3% HC<=200ppm ...(CAT test)
It seems you have quoted both, as well as the confusion as to whether the Mckay rule is applicable for cars with <6 seats.
Later..
The "Which is the same as for vehicles carrying 6 passengers or more." is not shown on the VOSA flowchart - it goes to another separate set of criteria (they may be the same - I dont know) BTW.
Now most folk probably could'nt be @rsed to read all this & are more than likely just to believe the first sentence they read? I do suspect that what your MOT tester told you is correct - but I just think that damned bobmacky text is wrong! You just unfortunately tried to use to justify what was correct
I can quite understand that you were reading what you wanted to see - not what was actually on the page, cue English interpretation war 
BUT I STILL dont see what any of this has to do with removing precats ~ the main cat is adequate when hot according to accepted beliefs (I think?). If this is not the case it is quite important. You are intimating that @80% of our cars NEED precats to pass MOT - that is pretty significant, as well as being against everything knowledgeable people have told me. TBH the only use I can see for this data is that it may be possible for some pre 31/7/95 cars to pass emissions with no catalytic converters installed (ie main cat out as well), but that may be me clinging on to my belief that the World is round.
Dave
The verbose extract of your first link:
bobmckay said:
Passenger cars:
* First used before 1/8/1975 - Visual test only. Failure for excess idle speed, dense blue or black smoke for 5 seconds at idle or during acceleration up to 2500rpm or half engine max speed whichever lowest.
* First used between 1/8/75 and 31/7/86 - meter test CO <=4.5%, HC<=1200ppm.
* First used between 1/8/86 and 31/7/92 - meter test CO<=3.5%, HC<=1200ppm.
* First used between 1/8/92 and 31/7/94 - advanced emission test (CAT) if its running on petrol when presented, to the vehicle specific limits usually around CO<=0.3%, HC<=200ppm and Lambda 0.97 - 1.03. Remember from 1st August 2001 a basic emission test will be carried out initially.
Note that the tests vehicles for first registered on or after 1/8/92 require expensive exhaust gas analyser equipment which is usually only available to the trade. However, there is DIY equipment available which is relatively inexpensive to enable emissions tests on vehicles prior to that date.
Vehicles with 6 or more seats are not passenger cars and are subject to less stringent requirements usually:
* Registered between 1/8/92 and 31/7/94 - meter test CO<=3.5% HC<=1200ppm
* Registered on or after 1/8/94 and an exact match can be found in the DTP data book or analyser database then CAT test to specified limits otherwise CO<=3.5% HC<=1200ppm
Which to me implied that highlighted part all (& only) applied cars with >=6 seats
You seemed to be wishing to quote the first highlighted rule as being applicable to you. This quite naturally confused the poo out of me, so I pointed it out (only to be told I had'nt been @rsed to read it?).
Then you go on to quote a VOSA document. If you actually read the 2 test criteria you've referenced they are different. Does that not raise some concerns? Are they just plain wrong, superceded, or plain out of date? - I think that is a classic case of causing confusion!
Now Vosa seems to state:
Put on the road 1/8/92-31/7/95 = CO<=3.5% HC<=1200ppm (nonCAT test)
Put on the road 1/8/95-31/8/02 = CO<=0.3% HC<=200ppm ...(CAT test)
It seems you have quoted both, as well as the confusion as to whether the Mckay rule is applicable for cars with <6 seats.
Quinny said:
Looks like you can't be arsed reading the link so I'll highlight the relevent bit for you.....
Registered between 1/8/92 and 31/7/94 - meter test CO<=3.5% HC<=1200ppm
Registered on or after 1/8/94 and an exact match can be found in the DTP data book or analyser database then CAT test to specified limits otherwise CO<=3.5% HC<=1200ppm
....
So the car has to be tested as though it hasn't got cats. ie CO=3.5% and HC=1200ppm
Registered between 1/8/92 and 31/7/94 - meter test CO<=3.5% HC<=1200ppm
Registered on or after 1/8/94 and an exact match can be found in the DTP data book or analyser database then CAT test to specified limits otherwise CO<=3.5% HC<=1200ppm
....
So the car has to be tested as though it hasn't got cats. ie CO=3.5% and HC=1200ppm
Later..
Quinny said:
Is it a passenger car? YES
Was it used between 1/8/92 & 31/7/95 YES
Can you find an exact match in the analyser database NO
Carry out a non cat test CO=3.5% HC=1200ppm Which is the same as for vehicles carrying 6 passengers or more.
Was it used between 1/8/92 & 31/7/95 YES
Can you find an exact match in the analyser database NO
Carry out a non cat test CO=3.5% HC=1200ppm Which is the same as for vehicles carrying 6 passengers or more.
The "Which is the same as for vehicles carrying 6 passengers or more." is not shown on the VOSA flowchart - it goes to another separate set of criteria (they may be the same - I dont know) BTW.
Now most folk probably could'nt be @rsed to read all this & are more than likely just to believe the first sentence they read? I do suspect that what your MOT tester told you is correct - but I just think that damned bobmacky text is wrong! You just unfortunately tried to use to justify what was correct
I can quite understand that you were reading what you wanted to see - not what was actually on the page, cue English interpretation war BUT I STILL dont see what any of this has to do with removing precats ~ the main cat is adequate when hot according to accepted beliefs (I think?). If this is not the case it is quite important. You are intimating that @80% of our cars NEED precats to pass MOT - that is pretty significant, as well as being against everything knowledgeable people have told me. TBH the only use I can see for this data is that it may be possible for some pre 31/7/95 cars to pass emissions with no catalytic converters installed (ie main cat out as well), but that may be me clinging on to my belief that the World is round
. Dave
Thanks Quinny
I have been looking for a legal way to kill the cat. Mine is of the November 94 vintage, so this could be just what I needed to know.
The link you gave
[url]www.vosa.gov.uk/vosacorp/repository/7.3%20Emmissions%20-%20Spark%20Ignition%20-%20Passenger%20Cars%201992-2002.pdf[/url]
Is a single page and I don’t seem to be able to get into the rest of manual. Can you post links to the other relevant pages, including the database please?
If the Griff is not in the database, can that database be amended for old cars, or is it fixed for all time? What I want to know is, if I remove the cat, will I find at some future date that the Griff has been added to the database and I have to put the cat back?
I think we need to find out if there is this loophole based upon the absence of database entry, what the limits are. Once we know what date Griffs or Chims are listed from, then we can advise the lucky owners of cars registered before that date and arm them with the relevant documentation to allow them to de-cat and pass.
I have been looking for a legal way to kill the cat. Mine is of the November 94 vintage, so this could be just what I needed to know.
The link you gave
[url]www.vosa.gov.uk/vosacorp/repository/7.3%20Emmissions%20-%20Spark%20Ignition%20-%20Passenger%20Cars%201992-2002.pdf[/url]
Is a single page and I don’t seem to be able to get into the rest of manual. Can you post links to the other relevant pages, including the database please?
If the Griff is not in the database, can that database be amended for old cars, or is it fixed for all time? What I want to know is, if I remove the cat, will I find at some future date that the Griff has been added to the database and I have to put the cat back?
I think we need to find out if there is this loophole based upon the absence of database entry, what the limits are. Once we know what date Griffs or Chims are listed from, then we can advise the lucky owners of cars registered before that date and arm them with the relevant documentation to allow them to de-cat and pass.
GreenV8S said:
Anyone here got any experience of trying to pass a 'cat' emissions test just using the precats (i.e. no main cat)?
Now that would be interesting to see. After all the amount of CC in each pre-cat when individually added together would prehaps not be to much difference in restrictiveness/size than the main cat?
BB
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