At the moment I am trying to diagnose why my Lexus is throwing a check-engine light code... It appears something with the charcoal canister and various vacuum test valves isn't working right. Talk about RAT'S NEST. It is a complete spaghetti of vacuum hoses, solenoids and test valves to control the fuel vapors. The ECU runs various self-test features while you drive.
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I hope Tesla stays away from any kind of infernal combusion engine. Emissions control systems are a whole other engineering challenge I hope they never have to work on.
Example of something similar which is one piece of the system:
