Do the Lexus ls430 have timing belts and if so when do they need changed?

Yes. I normally make the first change at 120,000 miles. Subsequent changes are every 100,000 miles

My LS430 Premium Pack Model year 2000 was told to do it by Lexus at 100,000mls which is what I did.

Manufacturer days 90k for t belt replacement.

I was told to get one at 65,000 miles and I have 45,000 miles, but since it is a 2006, they said I needed one because of age, not miles.