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Q: Having trouble with trouble code P0455.

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I bought this chevy cavalier from a used car dealership, three days later check engine light came on. I scanned it and gave me trouble code p0455. I replaced fuel cap with the aftermarket fuel cap and two days later the light came back. I then replaced it with the OEM fuel cap and two days later the light came back. I kept smelling gasoline everytime I opened the hood with the car running. I had a mechanic check it and told me it was the fuel pressure regulator, I touched it and sniffed my finger and you could smell the heavy gasoline odor. After replacing the regulator, I no longer smell gasoline on the car, but two days later the check light came back. Next the mechanic replaced the evap vent solenoid, and two days later the light came back. My question is what else could be the problem? I dont smell fuel anymore, there are no leaks under the car, the cars runs great and starts up great. I also dont hear any noises coming from car. By the way p0455 is the only code the car has.

My car has 82023 miles.
My car has an automatic transmission.

Hi. Trouble code P0455 is for the emissions system of the car and the only effect it will have on the car is the fuel economy may go down slightly and the car will pollute the air a little more. This code will not cause the car to run rough or shut down.

Now there are serval other components to your emissions system that could be still leaking causing this code. There are evaporative hoses that could leaking or completely broken causing this problem. The charcoal canister could be bad or have a leak in it as well. The best way to figure out this problem is too have a smoke test done and that should expose were the leak is in the emissions system.

Most local shops or the dealership has the smoke machine to perform the test. Alternatively, consider YourMechanic, as one of our mobile technicians can come to your home or office to properly diagnose the trouble code firsthand and help you make the necessary repairs.

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