Toyota 4Runner rough idle and stalling issue after engine warms up on Toyota 4Runner

Some Toyota 4Runner owners report experiencing rough idle and stalling issues after the engine warms up, often attributed to vacuum leaks and spark plug problems. These issues can manifest as stalling at idle when in "drive" and fluctuating idle while in park, typically accompanied by a check engine light indicating a misfire. Owners have noted that specific error codes, such as P0100 (MAF Circuit Malfunction) and P0304 (Cyl 4 Misfire), may appear during diagnostic checks when these symptoms arise. Despite attempts to resolve the issues through component replacements like the fuel filter and ignition coils, some users continue to face challenges with rough idling. Regular maintenance practices, such as checking for vacuum leaks and ensuring the condition of spark plugs and the idle air control valve, are recommended to help prevent these problems. If difficulties persist, consulting a qualified mechanic or dealership for a thorough diagnosis is advisable.