OK, the more i read the more i think he's testing with the wrong limits!
Has anyone got a link to some definitive answers?
E D I T
http://www.motuk.co.uk/images/7.3page6.pdf" onclick="window.open(this.href);return false;
4.5% CO
1200ppm HC
He's got it wrong!
Exhaust Emissions - Spark Ignition - non CAT Test Spark Ignition - Non CAT Test Flowchart
Information Method of Inspection Reason for rejection
When to do the test
It Is recommended that the engine is tested as soon as possible after driving on the road
.
B. Vehicles first used on or after 1 August 1975
1. Check that the analyser probe can be inserted into the tailpipe.
2. Use a suitable exhaust gas analyser to
determine the proportions of carbon monoxide {CO) and hydrocarbons (HC in the exhaust gas over a period of at least 5 seconds at idle.
Note: Any residual hydrocarbons (ie those indicated by the analyser when it is sampling only clean airj should be deducted from the HC reading obtained from the vehicle.
Note: If a vehicle meets the CO requirement at its normal idling speed but fails the HC check, re-check the HC level at a high idle speed of 2000rpm. If the HC reading is 1200 ppm or less, the vehicle will meet both the CO and HC requirements.
. the CO requirement must be met with the engine running at its normal (low) idling speed
. do not use a cold start/cold running mechanism to achieve a high idle speed. Instead, apply light pressure to the throttle pedal.
. HC not applicable to Compressed Natural Gas (CNG) fuelled vehicles.
B. Vehicles first used on or after 1 August 1975
1. The emissions cannot be measured because a tailpipe accessory is fitted which prevents Insertion of the analyser
probe
2. The exhaust gas contains
a. a carbon monoxide content
exceeding the limit for a continuous period of 5 seconds
b. a hydrocarbon content exceeding the limit for a continuous period of 5 seconds.
).
