Toyota Repair: charcoal canister replacement Toyota 4Runner check engine light on, charcoal canister, toyota 4runner

Question
I have a Toyota 2002 4Runner, got the check engine light on again after a few attempts and about $2000 spent at the dealer...now I was told that the the charcoal canister needs to be replaced for $650.  Is there a way to determine that this is really the problem and not something else that is causing this code to appear in the computer.  I want to avoid going back to the dealer again.  By the way I have 74000 miles....An answer is greatly appreciated....

Answer
Merita,

It sounds like the dealer is guessing at the problem. These are called PO440 codes and they will not affect how the vehicle runs. It is mainly concerned with emissions of evaporated gasoline from the gas tank.  It can be a simple problem of a bad gas cap to a more complex one. As for the charcoal canister they don't normally go bad unless the vehicle was in an accident causing physical damage to it. I would suggest trying your local salvage yards for that canister. The proper way to diagnose these problems is with a smoke machine. Yes, it basically fills the system with smoke and you can then see where the leak is. Problem is that smoke machines are expensive and your dealer probably does not have one so they are guessing.  I suggest calling a few other shops and ask if they have the smoke machine and are good at evap emission code diagnosis. Also, look for ASE certified technicians and check the shop against the better business bureau at BBB.org

Good Luck!!