Skip the auto shop - Our mechanics make house calls

Q: Having trouble with trouble code P0455.

asked by on

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.

A: Hi. Trouble code P0455 is for the emissions...

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.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Why is my car violently shaking and my check engine light and HOLD light are flashing?

Hi There, This can happen for many different reasons. The check engine light will come on when any of the following issues are detected by your vehicle's computer. Shaking or vibration may be caused by things such as faulty spark...

Q: Trac Off, ABS, and service lights

Hello, when you have a light on for a system it indicates a fault with that system. The ABS and traction control system are link together using the same input information for the computer’s operation. ABS (anti-lock brake system) prevent...

Q: My Pontiac G6 won't crank and wont start

I believe your "no crank" issue is the passlock security system has locked things down because of what it perceived as a "battery swap". If the car restarted after the jump as you indicate, the ECM is probably OK. The...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.