Why wont my 2000 Lexus Es300 accelerate when I press the gas until I put it to the floor?

A mechanic has had my vehicle for 2 days now, no one can figure out the problem, please help.

could be a number of reasons, could be anything from poor quality gas to a worn out accelerator pedal, you may require your local shop to run the diagnostics on this automobile to find out the problem.

Thank you for your response. I do run 87 oct. which could be part of it. At first they thought Catty'. At a dead stop when I take off if I barely hit the gas, it wont go until I lay into it and then it kicks you back and takes off, then rev's down unless I lay into the pedal again. Pedal seems fine.

My RX330 did the same. I was running 87 octane too. I switched to 91 and added Berrymans for 3 tanks and it cleared up and never occurred again.

Thank you very much for your reply, everyone thought it was sensor related???

02 sensor

Did you get this fixed ?