Toyota Repair: lag on accelleration when climbing, air sensor, accelleration

Question
QUESTION: Have a 2000 Lexus 300RX...RECENT AIR FILTER CHANGE AT LOCAL garage.use 85 octane always

ANSWER: Does the check engine light turn on or flash while this is going on?

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QUESTION: No ...but the check engine light has come on in the past...20000 miles ago... once or twice they(Toyota) changed the air sensor. Presently the check engine light is not on...

Answer
I would still check to see if there are any pending codes or in history by haveing the computer scanned, most autoparts stores like Autozone offer to do this at no charge, please reply back when you have any information, I'm looking for trouble code numbers, let me know if there are any or not.