One problem related to brake sensor has been reported for the 1998 Toyota RAV4. The most recently reported issues are listed below.
Engine light came 0n. Consumer applied brakes, and vehicle went forward and jumped curb. Consumer's vehicle hit another vehicle, and light went off. Next day, dealer checked system's computer and a sensor kicked up the idler. Sensor will have to be replaced. Consumer was unaware of the cause, and if it was an intermittent problem.