Buy OEM 1999 Lexus Part # 8942178020 (89421-78020). Turbocharger Boost Sensor. Turbocharger Boost Sensor - Repair or Replace If your turbocharger boost sensor has failed, you’ll notice both

TURBO PRESSURE, NO. 1; TURBO PRESSURE, NO. 2.

SENSOR, TURBO PRESSURE, NO.2 SENSOR, TURBO PRESSURE, NO.1

Fits GS 200t, GX 550, IS 200t, IS 300, LS 500, LX 600, NX 200t, NX 300, NX 300h, RC 200t

Turbocharger Boost Sensor - Repair or Replace
If your turbocharger boost sensor has failed, you’ll notice both a check engine light and that your turbo doesn’t spool up—the end result being poor acceleration. Lexus technicians are familiar with your 1999 Lexus and can perform the proper repair with genuine parts.