MOT & Emissions

[dubmeister]

I think it depends how many of the 30s the pipe stays in the exhaust

But when you remove the pipe the lambda goes down and it will fail on that!!!!!!!

[Rusty]

Fair enough...

Not sure what's going on, will get my RR place to check it as I'd hope their kit is quite accurate. Needs an RR session soon anyway to see how 300bhp is progressing... :mischeif:

[mcandmar]

Heres a thought, is there an equal gas flow through each tailpipe? Bet there isnt

[Rusty]

Who knows...

[UR-S4]

not legally no, gues your mot man is a keeperany car made from 92 onwards i think it is will be on the cat regs, and any car made before then that had one from the factory, but since no mot tester can every be bothered to find out your basically safe. a friend of a friend is an mot tester tho and he said if you have a decat pipe, a lot of mot station test systems atomatiaccly go onto the non-cat ststem assuming its a pre 92 so you'll pass unless the mot man has a sharp eye and notices the auto detect.

end of the day, i always thought sports cats were so expensive as they can do the job of the normal cat and flow more air...otherwise whats the point.....

Ant

LEGALLY YES.If the car fails an initial cat test you have to test it to published limits.If you have an ABY code s2 those limits are not published,so you test as a non cat vehicle.3B & ADU have published limits to work to so they have to have a cat test.(within those published limits)

[Rusty]

What are the limits for an RS2 then?

I need to get the emissions tested again but I'm pretty that the sports cat isn't working, what's the point of spending £200 on it

[s2driveruk]

thats rubbish, whoe point of a sports cat is more flow and the ability to remain legal. Sounds like something isn't right there Andy for sure.

[Rusty]

Yeah, will get it tested and see what's what. Have emailed the exhaust place to see what they say... not expecting any miracles. I'm fairly sure the car is in GWO, it's running well at the mo and had had a 100 mile run before the MOT.

[S2central.net]

I'll try to dig up the emissions tests for 3B and ADU...

The 3B data includes a CO test that is taken with a sniff pipe on the DP/EM - An ABY should be in same territory.

[s2driveruk]

taken from an old thread which i posted on on www.motforum.com :

Spark ignition vehicles first used on or after 1st August 1992 will require a BET test (a quick CAT test) limits: CO<=0.2%, HC<=200ppm, Lambda 0.97 to 1.03.

If it fails to meet these limits, a full test is required that has various limits depending on the vehicle tested.

1/Aug/1992 to 31/Jul/1995: if an exact match is found in the analyser data / emissions book then those limits must be used.
If no exact match, then a non-CAT test is done to limits CO<=3.5%, HC<=1200ppm

1/Aug/1995 to 31/Aug/2002: either a vehicle specific cat test is done, or a default cat test CO<=0.3%, HC<=200, Lambda 0.97 to 1.03, idle co<0.5%. This depends on whether vehicle is in analyser data / emissions book.

The Audi S2 is listed in the book so it has specific parameters to be measured against.

HTH
David

[GT500]

Just tested mine yesterday..
No cats and big fat fail.
co 0.96%
hc 251ppm
lambda 1.012 pass

Go back to work and refit cats.
co 0.01%
hc 23ppm
lambda 0.999

pass..

[s2driveruk]

so, in a nutshell Andy, your CAT is f****kin miles out at 7.3% and doesnt seem right at all. either something has failed or you have been sold a duff cat? is it a 200cpi unit or 100?

[s2driveruk]

3b test data:

Audi Coupe S2 2.3l injection Engine Code 3B Model Year 90-94
Max limits: Idle co 0.5%, idle speed 740-860
Fast idle co 0.3%, hc 200, lambda 0.97-1.03, fast idle rpm 2500-2800

[s2avant]

.

The Audi S2 is listed in the book so it has specific parameters to be measured against.

HTH
David

But only the 3B. ABY is not listed in the book so defaults to non-CAT test.

Based on Andy's experience it would appear that my sport cat is doing a better job in a box under the stairs than it would if I actually fitted it.

Ben

[S2central.net]

so, in a nutshell Andy, your CAT is f****kin miles out at 7.3% and doesnt seem right at all. either something has failed or you have been sold a duff cat? is it a 200cpi unit or 100?

@Dave - watch that decimal point. Rusty said 0.73% - which sure implies the CAT is almost useless - or test was duff.

Anyways - from this info that no published data is available for ABY then he should have no problem getting a pass with the CAT removed.