There is from time to time some confusion that reigns over MOT emissions tests carried out on Minis. For the most, it is fairly straight forward, but for the few, it can be a nightmare.
If you have a post 92 Mini, it can sometimes become an nightmare at MOT time, mainly down to the monkey carrying out the wrong test. Below is the current MOT emissions standards for the Mini in order of oldest first youngest last in logical order.
All vehicles Pre 1st August 1975 - Visual Only
All vehicles Post 31st July 1975, Pre 1st August 1986 - less than 4.5%CO and less than 1200ppm HC
All Vehicles Post 31st July 1986, Pre 1st August 1992 - less than 3.5%CO and less than 1200ppm HC
(this is where it gets complicated)
All vehicles Post July 31st 1992 Pre 1st August 1995 - 'BET test'. Natural idle - less than 0.3%CO. Fast idle - less than 0.2%CO, Less than 200ppm HC, between 0.97 and 1.03 Lambda.
If the emissions result from the 'BET test' is a fail, the Tester must then look for vehicle specific data and carry out a 'CAT test' or 'Non CAT' test depending on the available data as explained in the next paragraph. (Chances are any Mini will fail the 'BET test' especially without a catalytic converter)
All Vehicles Post 31st July 1992, pre 1st August 1995 - 'CAT test' - Can the Tester find an exact match in the analyser database or the In-Service Emissions book?
Reffering to the Vehicle Vehicle Identification Number
Mini - Model Code XN
1.3l Auto TBi/SPi VIN - Engine Code X, Serial No 059845 onwards. Natural idle - less than 0.75%CO. Fast Idle - less than 0.3%CO, Less than 200ppm HC, Between 0.95 and 1.09 Lambda.
1.3l Manual TBi/SPi VIN - Engine Code X, Serial No 059822 onwards. (Engine Number - 12A2D non Cooper or 12A2E Cooper) Natural idle - less than 0.75%CO. Fast Idle - less than 0.3%CO, Less than 200ppm HC, Between 0.95 and 1.09 Lambda.
If the Tester can match the VIN to the above information, the vehicle specific data above will be used to carry out a 'CAT test'. The catalytic converter MUST be present where fitted as standard. If the Tester cannot match the VIN to the vehicle specific data, the following data is used for a 'Non CAT test' - Less than 3.5%CO, less than 1200ppm HC. Catalytic converter does not need to be present.
All vehicles Post 31st July 1995, pre 1st August 2002 - 'CAT test' - Can the Tester find an exact match in the analyser database or the In-Service Emissions book?
Mini - Model Code XN
1.3l TBi/SPi VIN - Engine Code Y, Serial No 060488 onwards. (Engine number - 12A2E) Natural idle - less than 0.75%CO. Fast Idle - 0.3%CO, Less than 200ppm HC, Between 0.95 and 1.09 Lambda. Catalytic converter MUST be present.
1.3l MPi VIN - Engine Code Z, Serial No ALL. (Engine number - 12A2L) Natural idle - less than 0.5%CO. Fast idle - less than 0.3%CO, less than 200ppm HC, between 0.95 and 1.09 Lambda. Cataltic converter MUST be present.
If the Tester cannot match the VIN to any of this data, the following default data will be used - Natural idle - Less than 0.5%CO. Fast idle - Less than 0.3%CO, less than 200ppm HC, between 0.97 and 1.03 Lambda. (note that these limits are tighter than the vehicle specific). Catalytic converter MUST be present.
If the engine fitted is an older engine, emissions may be tested to the data the engine relates to. It is up to the person presenting the car to the Tester to to prove the engines age and identity.
Either way, the emissions test is carried out to whichever is oldest, the car (VIN checked against VOSA In service data) or the engine (up to you to provide valid proof of engine identity and age).
To summarise.
Any Mini pre 1st August 1992 there should be no reason it will not pass an MOT emission test.
Any Mini Post 31st July 1992 will require the MOT Tester to ensure he is carrying out the correct test by following the procedures laid out in the VOSA MOT Inspection manual, also reffering to the VOSA In Service Exhaust Emission Standards For Road Vehicles, or following the MOT analyser computer's instructions (it is this that the monkey either doesn't know how to, or just can't be bothered to, wich can lead to an unjustified fail). If you read the above information for 92 to 95 cars carefully, you can see a loop hole, since if emissions fail on the 'BET test', and the VIN does not match the vehicle specific data, the Tester should use the 'Non CAT test' data. Any Mini in this catagory should have no reason to fail the 'Non CAT test'. Remember that if the car is tested with a 'CAT test', the catalytic converter MUST be present. It would likely fail without the cat anyway in that case.
Any Mini post 31st July 1995 will have to pass at the very least a 'CAT test' with default data (which is tighter than the vehicle specific data) and there MUST be a catalytic converter present. This is of course dependant on the age of the engine, and it is up to the person presenting the car at the test station to provide proof of the identity and age of the engine.
