Cats and the MOT for an S2

[Azman]

Well last MOT my CQ20 just passed on emmisions (and it did have a cat) now new engine and no cat (shortly to be 3" turbo back system) I'm a bit scared for when it comes round next feb.
Just for your info though the local garage where I get my MOT's done says pass emmisions with or without cats and there is no problem......
Wonder how some of the chavs with their boy racer cars manage it (Oh yeah forgot, the cars are usually nova's and that cheap they replace the car every time they need an mot

[s2driveruk]

Guys, here is a reply i just recieved from MOT forum....

In general (there may be variations depending on vehicle type):

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<=0.5%, 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.

[s2driveruk]

and the news i didn't want confirming:

David, that vehicle will need a vehicle specific cat test:

From the 'In Service Exhaust Emission Standards for Road Vehicles' 12th edition:

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


Sh*t!

[ian_jemo]

So i presume de cating your car increases the performance and sound?

I take it the gains are not alot