Review on GM Genuine Parts 215-608 Vapor Canister: Superior Quality and Performance by Ryan Gilliam

I had to replace the canister on my 2007 Silverado due to an evap code. During the built-in evaporator test, it closes the evaporator solenoid and allows the system to draw a vacuum, then opens the solenoid and measures the rate of vacuum loss. My vacuum level dropped too slowly after opening the solenoid because the canister was clogged, which set off the evaporative code. After I replaced the canister the vacuum immediately went away and the test passed and the check engine light went out. The old one lasted 12 years so not too bad.