The fuel evaporative system (EVAP) controls emission by housing vapors from evaporated fuel and sending them back to the fuel tank to be reused. The cost for EVAP system repair ranges between $200 and $560. The labor alone will cost somewhere between $35 and $140, while parts will run somewhere between $150 and $440.

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.

How to deal with failed emissions test and high HC

1. What causes high HC?
2. Diagnose high HC.
3. Start by reading short term and long term fuel trims.
4. Checking for vacuum leaks and air leaks.
5. Check for leaking fuel injectors.
6. Check for leaking coolant.
7. Bad catalytic converter.

Ignition defects including dirty spark plugs, leaking or open-circuited spark plugs or wires, or defective ignition coils can all result in a shortage of spark energy. Any shortage of spark energy may cause high HC emissions. If the spark occurs at the wrong time, incomplete combustion and high hydrocarbons may result.

But there are things you can take into account to improve your driving and ways to maintain your car to ensure you are reducing your car’s emissions as much as possible….

1. Use a cleaning agent.
2. Use better fuel.
3. Change the oil.
4. Change the air filter.
5. Check your tyre pressure.
6. Air conditioning system.
7. Reduce idle time.

One or more bad plug wires, ignition coil(s) or a bad distributor are other suspects. High CO (carbon monoxide) emissions usually result from a lean (too little fuel) air/fuel mixture. A dirty air filter prevents sufficient oxygen (from the air) from entering the engine in ratio to the amount of fuel.

Sea Foam can help your vehicle run cleaner and greener, which is a win for all of us. So if you’re looking for help passing an emissions test, or you just want a better running car or truck, try this: Follow the fuel treatment with a sequence of two Sea Foam Spray treatments through the intake.

One reason for a failed emissions test is an overdue oil change. Your vehicle’s manual should tell you how often you need to change your oil, and skipping these important milestones can result in failing marks during an emissions test. Dirty oil in the crankcase could release additional pollutants, reports Edmunds.com.

A dirty air filter is one of the things that can cause your Check Engine light to come on, caused by an inadequate supply of air to the engine that results in a buildup of carbon deposits. Have your mechanic scan your vehicle to track down the source of the problem, as it could be as simple as replacing the air filter.

Air Filter Appears Dirty. A clean air filter appears white or off-white in color, but as it accumulates dust and dirt, it will look darker in color. However, very often, the inner layers of filter paper inside the air filter might have dust and debris that is not visible even in bright light.

In vehicles with an oil-soaked aftermarket air filter, oil from the air filter can contaminate the MAF sensor element, causing the code P0101 or other MAF-related codes. In some Volvo cars, the code P0101 could be caused by a dirty throttle body or vacuum leaks in the PCV system (e.g. vacuum line to the oil separator).

Here are some of the most common symptoms of a faulty mass airflow sensor:

1. The engine is very hard to start or turn over.
2. The engine stalls shortly after starting.
3. The engine hesitates or drags while under load or idle.
4. Hesitation and jerking during acceleration.
5. The engine hiccups.
6. Excessively rich or lean idling.

If you plug it in it will die if the car is running. If you unplug the mass air flow sensor the car will start. If you try to plug it in while it’s running the car will die.

Stalling, jerking, or hesitation during acceleration A bad MAF sensor can cause too much fuel to be left in the combustion chamber, creating untimed detonations. You’ll experience this as poor drivability such as hesitations or sudden jerking motions, particularly during acceleration.

The MAF sensor measures air weight in grams per second and air temperature and if either of those two are off then the ECU may command a leaner or a richer mixture. By disconnecting the sensor the ECU switches to limp mode and the car may idle better .

If you disconnect the mass airflow sensor, then the car should keep running and still be able to start normally. This means that if your mass airflow sensor dies completely, then your car will stay running and surprisingly the car might run better without the mass airflow sensor.

Can you bypass MAF sensor? There is a sensor on the air intake called the mass air flow sensor. This sensor calculates how much air to mix with the fuel. You can bypass the MAF sensor, and allow the O2 sensor to calculate how much air is needed.

What difference does having a maf in the OTR make to performance? It makes next to no difference in maximum power compared to a mafless tune. However there are benefits of tuning the car not using a maf as long as it is done properly which is much more involved and harder to develop for the tuner.

It is not advisable to drive your vehicle with the MAP (manifold absolute pressure) sensor disconnected. With the MAP sensor disconnected, the fuel delivery will be excessive and could cause harm to the engine and exhaust system (catalytic converters).

A contaminated or failed mass air flow sensor cannot measure the amount of air flow correctly. This causes the engine computer to miscalculate the amount of injected fuel. As a result, a bad mass air flow sensor causes various driveability problems, including a no-start, stalling, lack of power and poor acceleration.

If an oxygen sensor or mass airflow sensor is failing, it could give incorrect data to your engine’s computer, causing the misfire. When a vacuum line is broken, it can cause a fuel-injected motor to misfire. Replacing a vacuum line that’s gone bad can potentially resolve the misfire.

How to Clean a MAF With Alcohol

1. Locate the mass air flow sensor on your vehicle, which will be under the hood.
2. Remove the MAF sensor from the vehicle.
3. Pour isopropyl alcohol in a clean spray bottle.
4. Spray the alcohol liberally over the MAF sensor.
5. Place the wet MAF sensor on a clean shop rag or paper towel.

Set your meter at or close to 10 V DC. Start the engine and let it idle. Backprobe the signal and ground wires (red probe to signal and black probe to ground). Depending on your MAF sensor, your voltage reading should be between 0.60 to 0.80 volts at idle.

You can drive your vehicle with a bad mass air flow sensor for a while, but it is not advisable to continue doing so for a long time even if your car can still run and that is because, Ignoring your car MAF sensor problem can escalate beyond just the Mass air flow sensor problem to a more severe engine problem that …

You can’t use carburetor or brake cleaners on a MAF sensor, as the chemicals in those cleaners can destroy the delicate sensors. Instead, a special MAF sensor cleaner is required. CRC MAF Sensor Cleaner is specifically designed to remove oil, dirt, fibers and dust from the sensor without damage.

Mass Air Flow Sensor (MAF) A dirty or faulty MAF will cause an engine to idle roughly, as well as stall when idling.

The downsides of a rough idle can be reduced fuel economy, poor performance, starting issues, or potential major engine problems in the near future. It is best to try to diagnose and fix a rough idle before it gets worse and before it gets expensive!

The short answer is yes. But $1400 is way too much. I would try replacing the mass air flow unit, clear the codes and run the truck, if you get lucky maybe the light won’t come back on.

1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF.
3. Disconnect mass air flow sensor harness connector.
4. Restart engine and let it idle for at least 5 seconds.
5. Stop engine and reconnect mass air flow sensor harness connector.
6. Make sure DTC P0102 is displayed.
7. Erase the DTC memory.