What Are the Causes of a High Hydrocarbon Reading During a Smog Check?
- Hydrocarbon Emissions. Motor vehicle fuel contains hydrocarbons, which are its primary source of energy. Any...
- Ignition Problems. Ignition timing issues may cause a failed smog test, either through a functional failure or through...
- Fuel Mixtures. Both lean and rich fuel mixtures affect the level of...
What causes HC emissions to be elevated?
What causes high HC readings on emissions test? Lean Fuel Mixture - Any condition which will cause unmetered air to enter the intake manifold, and ultimately the combustion chambers, will cause high hydrocarbons (HC). This condition is called a lean miss-fire. Such faults as vacuum leaks and gasket leaks will cause lean fuel/air mixtures.
What does a high HC reading mean on an emissions test?
What causes a high HC reading on a car?
What causes high hydrocarbon emissions in a car?
How can I lower the HC emissions on my car?
On a precomputer carbureted car, one way to get under the HC and CO limits is to retard the ignition timing. This will slow the idle and provide a longer, hotter burn. Then, bring the idle speed back up to specs with the throttle stop screw or idle stop solenoid, which will admit more air.Dec 7, 2004
How do you fix high exhaust emissions?
Reducing your car's emissions is good for the environment and a cleaner car will also offer better performance, increased fuel economy and be cheaper to run....Use a cleaning agent.Use better fuel. ... Change the oil. ... Change the air filter. ... Check your tyre pressure.Air conditioning system. ... Reduce idle time.More items...•Sep 29, 2021
What does high HC ppm mean?
A high HC reading means the test found high HC (hydrocarbons) in your emissions. In other words, too much gas is left in the exhaust after combustion.Jun 24, 2018
How can diesel emissions be reduced?
An excellent way to reduce diesel emissions is to install a selective catalytic reduction (SCR) onto your car. The job of the SCR is to convert gases from NoX to either nitrogen or water vapour. This advanced emissions control technology system adds ammonia to the exhaust gases.Jan 27, 2021
How can I reduce emissions to pass MOT?
Typically, the agent should be poured into the fuel tank when your car has at least a quarter-tank of fuel. Once you have applied the fluid, simply go for a 10-15 minute drive and allow the agent to be flushed through your engine.Mar 4, 2021
What does HC mean on a smog test?
High HydrocarbonHydrocarbons are basically raw fuel, otherwise known as Gasoline. High Hydrocarbon (HC) emissions are almost always a sign of poor fuel ignition. However, it's not always that the engine's ignition system is responsible for high Hydrocarbon emissions. Read on.
What does HC ppm mean on emissions test?
Find "HC PPM" within the tailpipe section. You read this as hydrocarbon parts per million, and it means the number of hydrocarbon molecules for every million molecules emitted through the exhaust.
What would a high HC low CO and high O2 at the same indicate?
General Rules of Emission Analysis Remember, CO readings are an indicator of a rich running engine and O2 readings are an indicator of a lean running engine. High HC, high CO, and high O2 at same time indicates a misfire due to excessively rich mixture.
What causes high HC emissions?
Excessive HC results from ignition misfire or misfire due to excessively lean or rich air/fuel mixtures.
What causes high CO emissions?
High carbon monoxide levels are caused by anything that can cause a rich conditon.
What causes a failed smog test?
Ignition Problems. Ignition timing issues may cause a failed smog test, either through a functional failure or through increased release of hydrocarbons. If ignition timing measures before or after the point designated by the manufacturer, this causes premature or late firing of the spark.
What is the maximum smog reading required in Connecticut?
In the state of Connecticut, 150 parts per million is the maximum reading required to pass a smog test. The danger in hydrocarbon emission is in its combination with sunlight and nitrogen, which forms ozone.
What happens if a catalytic converter is not working?
A malfunctioning catalytic converter may also lead to a high hydrocarbon emission reading. The catalytic converter is designed to burn emissions so that the car exhaust is less harmful. Malfunction leads to increased levels of hydrocarbons and carbon monoxide. Additionally, the evaporation emission control system works to regulate gasoline vapors ...
How does a lean fuel mixture affect a vehicle?
Both lean and rich fuel mixtures affect the level of hydrocarbon emissions from a vehicle. An overly lean fuel mixture occurs when air is introduced to the fuel system and may result from vacuum or gasket leaks. Rich fuel mixtures contain higher than normal levels of carbon monoxide. A rich fuel mixture may occur from contaminated oxygen sensors ...
What is the maximum hydrocarbon part per million?
For example, in the state of California, the maximum hydrocarbon parts per million is 64 when the test is run at a simulated 15 miles per hour.
Why does my car fail smog?
A common reason cars fail smog tests is an excessive measure of hydrocarbons emitted into the air through exhaust. Increased hydrocarbon emissions develop from several places in a car's gasoline combustion system.
What are the components of a car's ignition system?
Additionally, components of the ignition system affect hydrocarbon emissions. Ignition components include ignition coils, distributor cap, rotor and spark plugs.