2007 Toyota 4Runner Owners Manual - Page 482
2007 Toyota 4Runner Manual
Page 482 highlights
06 06.07 Leak detection pump This pump performs fuel evaporation leakage check. This check is done approximately five hours after the engine is turned off. So you may hear sound coming from underneath the luggage compartment for several minutes. It does not indicate a malfunction. x 2007 4Runner from Aug. '06Prod. (OM35866U)