its a 2000 1.8t ATW engine, eliminated the CAT and the SAIP, getting an oil catch can soon. and was wondering what the EVAP valve does on top of the airbox. can it be eliminated or is it critical to the engine. trying to get rid of everything that doesnt help make power. hence the removal of the CAT and the SAIP. and im not worried about a CEL i has 10 code at a minimum all the time.