Knock sensors keep going out???
 

I just replaced both knock sensors in my 2002 Lexus ES300 along with the wire harness... Not even a week later and the check engine light is on again due to "knock sensor 1, circuit 1." Is there an underlying reason this sensor would keep going out? I have done some research and they say it may be due to low octane fuel. Has anybody experienced the same problem?

Did you buy aftermarket sensors or Original Toyota/Lexus sensors from the dealer? I'm If aftermarket, they are notorious for not being compatible with the car.

They were OEM parts, correct part#s. We are going to try premium gas and octane booster and reset the Check engine light and hope for the best

Forget about the premium fuel or octane boosters. Your problem lies somewhere else.

Try resetting the check engine light. Disconnecting the battery's for 10 min or so, will also let the computer re-learn your driving habits.