Visual Inspection
WARNING: This page is about a different car, the 1995 Lexus SC 300. However, it is still accessible from the selected car via links, so may be relevant.
Visually inspect all electrical wiring, looking for chafed, stretched, cut or pinched wiring. Ensure electrical connectors fit tightly and are not corroded. Ensure vacuum hoses are properly routed and are not pinched or cut. See VACUUM DIAGRAMS article to verify routing and connections (if necessary). Inspect air induction system for possible vacuum leaks.