This Management method reqires that every one four throttles be entirely closed when to the stops. The throttle by-go screws are manufacturing unit altered and set to equilibrium the throttles. The reality that your AFR's are regular even though driving says that your ECU is more than likely Operating OK. https://toyota-4age-engine-for-sa25680.isblog.net/4age-20v-no-further-a-mystery-49392287