For the past year and a half i had been fighting a problem with my 95 es 300. when vehicle was cold the car had absolutely no power. Even when warmed up the car was sluggish and just didn't have the power a v6 should. I used my scan tool and all sensors were withing spec. i swapped mass airflow sensors, tryed a different ecm, engine coolant temp sensor, checked fuel pressure, and all the sensors i replaced did nothing to help out the driveability problem. Fuel pressure was ok. I finally got some time on my hand and pulled the wiring harness out of the car and checked all wiring to make sure there were no shorts to ground or shorst to power. Everything checked out ok. I finally started disconnecting each sensor from the ecm one at a time and when i disconnected the knock sensors i found my problem. I found that I had an oversensitive knock sensor which kept telling the ecm that there was predetonation occuring all the time so the ecm was retarding the timing back so far the car had no performance. I didn't want to pull the intake off and spend close to $400.00 for 2 new knock sensors. I ended up installing for now two 10 ohm 1/2 watt resistor between the ecm and knock sensors. by doing this and using super unleaded i increased my gas mileage by between 50-80 more miles to a tank, since now i don't have to keep the gas pedal floored to keep up with traffic. The car drives like a bat out of hell now and i love the car. Hopefully, this information might help someone who is having similar problems with their es 300. I did take my car to lexus at one point and they changed the spark plugs, readjusted the tps sensor, and cleared ecm adaptions. Of course this didn't fix the problem and they couldn't find anything wrong with the car.
