Is it dangerous to drive before replacing anti knock sensor? What damage can it cause?
Not if you use some common sense, easy take offs, no hill climbing, light throttle, keep engine speeds down, and keep listening for engine ping, if you hear it back off the gas, slow down. I remember the worse case I saw caused severe piston damage.
tennisshoes is likely correct, but I wouldn't drive it. If you must drive it make sure you use premium fuel as it will help reduce any knock that happens.
Use premium gas in the meantime.
Looking for a Used ES 300 in your area?
CarGurus has 825 nationwide ES 300 listings starting at $1,500.
Search Lexus ES 300 Questions
Lexus ES 300 Experts
Related Models For Sale