P0455 Evap System Large Leak Detected ----> Chevy Aveo 2005 <-----

Hi Guys,
I'm getting a P0455 Check engine light code. Seems to happen about 4-5 minutes into driving after I clear the code (disconnecting from battery).

1- Tried tightening cap
2- cleaning cap seal


Does anyone have a diagram on the aveo that outlines this? I cannot seem to find a AVEO manual (like Haynes) since the car is not sold in the United States.
Anyone else experience this problem in an Aveo?

Thanks in advance
Paul





P0455Evap System Large Leak Detected

Technical Description Generic: EvaporativeEmission Control System Leak Detected (no purge flow or large leak) Chrysler:EVAP Large Leak Detected Conditions Ford: EVAP System Leak (No Purge Flow orLarge Leak) Conditions GM: EVAP System Leak Detected Conditions Nissan:Evaporative emission (EVAP) canister purge system - gross leak What does thatmean? This indicates a fuel vapor leak or lack of purge flow in the EVAPcontrol system. It means a large leak has been detected. The (EVAP) emissioncontrol system prevents the escape of fuel vapors from a vehicle's fuel system.Fuel vapors are routed by hoses to a charcoal canister for storage. Later, whenthe engine is running a purge control valve opens allowing intake vacuum tosiphon the fuel vapors into the engine. Symptoms You likely won't notice anydrivability problems. Causes A code p0455 most likely means one or more of thefollowing has happened: A loose or improperly affixed gas cap A non-conforminggas cap (i.e. not factory/original brand) Other leak or damaged piece in EVAPsystem Possible Solutions With a p0455, the most common repair is to: Removeand reinstall the gas cap, clear the codes, and drive for a day and see if thecodes come back. Otherwise, replace the gas cap, and/or Inspect the EVAP systemfor cuts/holes in tubes/hoses (you may hear a vacuum noise or smell fuel),repair if necessary

Look in the passenger rear wheel well and verify the condition of the evaporative emissions equipment. Then check under the hood for vacuum leaks. For the most part though, if any of the stuff in there leaks, you'll either leave wet spots, or smell gas. Even under the hood.

You can't 100% verify the cap isn't leaking without testing pressure. Our emissions machines in PA test gas caps for seal. But honestly it would be cheaper to buy another cap than to test it.

I had this code in my '05 and first tried a new cap. That didn't fix the problem, but replacing the vent solenoid did. I actually got one from a U-pull, and it's been working fine for over a year.

I wanted to observe and troubleshoot before replying.
Thanks for the replies.

Timeline:

1. Serviced K&N filter, cleaned breather tube and throttle body. Put normal paper filter back in for troubleshooting
2. Threw CODE P0455
3. Came on Aveoforumhere to ask.
4. Looked for leaks at:

• Vent Solenoid

• Hoses

• Canister is above tank or beside Vent Solenoid at right rear -NO OBVIOUS GAS LEAKS AS SUGGESTED

1. Cleaned AIT (Air intake temperature sensor) brake cleaner, then 100% ALCOHOL to clean off brake cleaner. Reinstalled Breather tube.

1. Disconnected battery and waited 1/2 hour

1. While waiting I cleaned sparks plugs lightly using wire brush to remove build-up. Piston head looked like it had build-up Reinstalled (blow out the spark plug area before removing!)
2. Tightened down valve cover since some oil leaking. Checked valve cover bolts torque at 10 NM, 11 NM, 12 NM, 13NM, 14NM 15 NM. Decided to use "feel" to tighten slightly. (Anyone have experience with valve cover bolts...what is the most I should tightened?!)

1. Reinstalled battery now with code clear. Degreased around/below valve cover, ran car with code cleared for 1/2 hour. Burning off degreaser. (Carbon footprint enter here)

1. Driven for 2 days. Code did return once on 1st day but has now not returned

• Vaccum leak?

• Vent solenoid valve (stuck open or working intermittently)

Ifcode returns, I will replace VENT Solenoid.
Will update thiswhen things change.

Not sure if cleaningoff the spark plug helped, but my car is sounding and shifting A LOT better!
Much smoother.

Thanks for your help
-NAttachment 10185

Replace the cap is a common fix. It might feel like it's sealing but most of the time not. BTW points for writing up a good time line of your troubleshoot.