I have a 2002 Lexus SC430.The car seems to occasionally lose power, where the RPMs will fall for no reason. The car does not die or stop, just a decrease. I do not let up on the gas, instead I have to step on it to accelerate back to speed. I change the oil, and even use synthetic. What could be the reason for this?. Created by Anonymous. cars-transportation-en - maintenance-repairs-en

hi.. the check engine light should be on, indicating a trouble code was stored. retrieve that code and replace related device to fix the problem. if no check engine light came on, check preventive maintenance replacement due on the fuel filter.it is possible also, that the fuel is contaminated , like water, or just bad fuel. :)