Designed through early 1996, in September 1997 a revised LS 400 was introduced for the 1998 model year. Changes were a five-speed automatic transmission, increased engine output to , with variable valve timing (VVT-i), and an added of torque. Acceleration times and fuel economy were improved as a result. The suspension and steering also received minor tweaks to improve feel and handling. Stylistically, the vehicle sported a new front fascia, side mirrors, and updated wheels; a rear window diversity antenna replaced the conventional power mast. The cabin received upgrades, including a trip computer, HomeLink, retractable rear headrests, reading lamps, and ultraviolet-tinted glass, while the climate control gained a micron filtration feature with a smog sensor.