complete maintenance? that's a heck of a lot of miles. at the very minimum i'd change the oil and oil filter, the fuel and air filter, the spark plugs, and the belts. then i'd have the timing checked and the air/fuel mix adjusted (if it's a carburated car), or, have the codes dumped if it's fuel-injected.
yeah, that's quite a bit of mileage, and on a 14-year old car to boot. but i didn't mention the expensive/scary problems first. cheap things first. but it's probably burning oil like an oil field in Iraq..
FWIW, the lexus I6 engine and the mazda KL03/KLZE V6 are supposed to last well beyond 200,000 miles with no problems.