I have a 1999 mod IS200 Sport w/automatic transmission... Same symptons as several other is200 post... running rough for a while then running ok, feeling lack of power and using a lot of fuel, engine running hot (but not showing on temperature gauge inside car).. and of course engine management lights and TRC flashing. Getting sick and tired of this problem. P0300, P0302 and P0305 are the diagnostic codes. (Multiple misfire, and misfiring on syl 2 and 5). Have changed all 6 spark plugs, and shifted the six coil packs around, reset the codes, but the engine light and trc comes back after a short while. The codes are the same P0300, P0302 and P0305 so the "problem" doesn't change sylinders, meaning that changing plugs and swapping coilpacks doesn't help. Have also cleaned the throtle body as suggested in some othe post. Wondering what to check next, too bad Lexus diagnostic isn't a little better at pinpointing the problem... of this problem, grateful for any advice..