Q: Code on computer showed P0455 and when I started my car It has a rough start it was shaking/sputtering

asked by on March 12, 2017

My car shows the check engine light and the computer showed code P0455 and it shakes and vibrates at stops and it shakes when I accelerate and today when I started it, it had a rough start it was shaking and sputtering and when I back up it sputters.

My car has 118000 miles.
My car has an automatic transmission.

Hi There, Generally, code P0455 relates to your evaporative emissions control system. This code can be triggered if you gas cap is not properly sealed or in the event that your evap system has a leak of some kind. Your car has a small purge valve with a purge solenoid in the Evaporative Emissions system that controls the venting of fumes from the fuel tank as these fumes build up inside, particularly when you are refueling the car with gas. The EVAP system prevents fuel vapors from the fuel tank from escaping into the atmosphere. The EVAP system collects and temporarily stores the fuel vapors in the charcoal canister. The charcoal canister is filled with activated carbon pellets that can absorb the fuel vapors. When the engine is running, the fuel vapors are purged from the canister and burned in the engine. The vent control valve (solenoid) controls the flow of outside air in and out of the charcoal canister. The vent valve is controlled by the engine computer (PCM). Normally the vent valve is open. It closes when the engine computer tests the EVAP system for leaks. If a leak in the EVAP system is detected, the Check Engine light will illuminate on the dash and the trouble code related to the problem will be stored in the engine computer. When an air leak is present in the EVAP system, the MAP sensor will not be able to determine the air density, and the MAF sensor will not be able to determine the volume of air, entering the engine correctly. This will lead to an over fueling situation or an under fueling situation depending on the size of the air leak and engine operating speeds and load. This may eventually lead to catalytic converter problems as well as misfiring problems. I would recommend having an expert from Your Mechanic come to your location to diagnose and inspect your vehicle.

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