When gasoline sits inside your fuel tank, it discharges fuel vapors which end up getting burned inside your internal combustion engine. The EVAP (evaporation emission control) system is responsible for directing the flow of the fuel vapors into the engine. If a vehicle had no EVAP system, then all those fuel vapors would end up going outside into the open air. The result would be more vehicle emissions which pollute the atmosphere and poison our lungs.
If the EVAP system experiences just a small leak, then it will increase the emissions of your vehicle and reduce its fuel economy. Then you’ll start to smell a fuel odor inside your vehicle. The Check Engine warning light may even come on too. These are all problems which cannot be left unresolved. You must run a diagnostic check to see how big the leak is. If you are given diagnostic code P0456, then it indicates that a small leak is detected in your evaporation emission system.
It is better to have P0456 than P0442 and P0455 because a small leak gives you more time to fix the problem. If you have a medium or large-sized leak, then it poses a bigger risk of damaging your charcoal canister, fuel tank, canister vent control valve, purge control valve, or EVAP pose. It all depends on which component is causing the leak in the first place.
Even though P0456 only indicates a small leak in the EVAP system, do not let this be an excuse for you to procrastinate on solving the problem. A small leak can always turn into a bigger leak if you don’t do something about it soon. Since your driving ability is not affected, take this opportunity to drive your vehicle to the nearest auto technician and have them figure out which component of the EVAP system is causing the small leak. It shouldn’t cost too much to repair the problem.
- P0300: Random/Multiple Cylinder Misfire Detected
- P0171: System Too Lean Bank 1
- P0420: Catalyst System Efficiency Below Threshold (Bank 1)
For instance, the average purge control valve costs between $150 and $200. The average charcoal canister vent control valve costs between $150 and $200 as well. An EVAP line replacement is between $50 and $100, while a new charcoal canister costs between $200 and $600.