Smllfry1

Trac off/ engine light & VSC lights appeared on My Lexus RX 350, So at the recommendation of this forum, I took my car to auto zone & had it read .
My error code was P0456
evap emission leak ( very small leak)
suggested parts: EGR Vacuum Solenoid
Can anyone explain what this is; Is it emergent & the possible cost.
I'm not a savvy woman when it comes to cars & any advice is greatly appreciated!

mdbrown

It's incredibly annoying but not emergent. It will stop you from passing a smog check though. Briefly, the evap system is designed to capture the raw fuel vapors and store them in a charcoal canister. It then vents these vapors into the engine to be burned. The system uses long runs of rubber hoses. The code occurs when the system pressurizes the fuel tank then checks for a pressure loss. If you clear the code you won't see it again for a while, typically after you refuel as it only runs it under specific circumstances. Any decent shop should have smoke machine they can use to determine where, if any, the leak is. It will also set if you leave your fuel cap loose.

kickin8

iTrader: (1)

What year is your RX ? I would start with the cheapest solution first : get a new gas cap....

05RX330AWD

I agree with the other CL Members...
That's a tough code to deal with, a tiny pin hole in a hose will set the code...
like looking for a needle in a haystack.
If the gas cap replacement doesn't solve the issue, a smoke test should.

5W40

Not emergent but emission related.

Clean gas cap first and put a thin layer of silicon-based grease or vaseline on gas cap rubber seal. if this trick doesn't work then you may need further diagnosis.

BlackLexRX

I had that exact code and a new gas cap fixed it. Could not see any problem with original cap or its o-ring or threads.