If you have recently failed your state mandated emissions test you might want to know why. Sometimes the fact that you failed just isn’t enough and we here at GIC Car Clinic in San Jose, California feel you should better understand the testing procedure and how your vehicle’s emissions equipment operates. We have compiled the list below of some of the more common reasons you may have failed the emissions test.
- Improper ignition timing:Whether your vehicle is an older model with a distributor or a newer car equipped with an ECU, the end result is still the same. The engine must be timed correctly. Even a difference of more than +/- 3 degrees could cause you to fail the emissions test and create higher hydrocarbon emissions.
- Defective ignition components:These include ignition coils, spark plugs and wires and distributor components. If any of these components are worn or defective, you will not get as hot of a spark or no spark to ignite the air/fuel mixture in the combustion chamber of the engine.
- Lean fuel mixture: This condition is caused by too much air entering the intake manifold and can create a higher amount of hydrocarbons. Causes of this are vacuum leaks at gaskets and hoses as well as disconnected or any improperly routed vacuum hoses.
- Low cylinder compression:Not as common as the other symptoms but can still cause higher than normal HC. An engine may have low cylinder compression because of bad rings, a bad head gasket, burned valves or bad valve seals.
- Faulty air injection equipment such as a smog pump can cause high HC emissions. This system injects air into the exhaust system to aid in the burning of any extra fuel.
- Faulty catalytic converter: Your catalytic converter plays an important role in your car’s emissions system and if it fails it can cause higher than normal levels of HC gases. Some signs that yours is going bad are:
- A major loss of power at driving range.
- A loud rattling sound like rocks in a coffee can. This is the internals of your catalytic converter breaking down.
- A sulfur or rotten-smell coming from your exhaust.