Good to be part of a LEXUS forum!
Anyway i did my oil change which i have always done myself (never had a problem). I used 5w-30 Mobil 1 synthetic with Mobil 1 filter, filled it with about 4 litres and took it for a drive. The oil light came on!! the 8 years i have owned this car and done the oil changes i have NEVER seen the oil light. WHATS UP!?!?