I had a quick question.....I have a 99 lexus sc300 and i recently got all tyres changed as well as the oil and did the 14 point diagnostic at firestone. I was driving one day and suddenly experienced a loss of power with the malfunction lamp on.....the car would not go ahead unless i pressed the accelerator 80-90 %..!!! i waited and was trying to call AAA to tow it before the car started driving at a sluggish rate.....next day the prob was fixed nd the MIL was off.......next day it happ again nd the lamp was on...!!! now its off again...!!!! any clues? i cant get the codes unless the MIL is on!!!.......

 

check your vacuum lines first