is one of the
most effective
vehicle emissions testing programs
in North America
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Repair Info - Emissions Repair Explained
Overview | Component Testing - Doing It Right | Induction System TestingInduction System Testing
The induction system is made up of hoses and ducting that may be rubber, plastic or metal, all of which direct outside air into the engine where it is combined with fuel and burned. Any leakage may cause an imbalance in the air/fuel mixture, and result in excess emissions. Extremely large leaks can also cause rough idle operation or even stalling.
A visual inspection for loose clamps and cracked rubber is easily done and should be the first step of any induction system testing.
To test for less obvious vacuum or air leaks, a diagnostic technician can use a variety of methods, all of which go beyond simply checking that clamps are tight. One method is to use a tool that generates thick white smoke and connects to the induction system with the engine off. Areas of leakage are indicated wherever the smoke escapes.
Another method is to hook-up a gas analyser to measure CO ahead of the catalytic converter (so readings aren't influenced by the cat) with the engine running. Then apply small quantities of propane near suspected areas of leakage. If a leak exists, the propane will be drawn in and the CO reading will increase.
