CLARKAA

I have a 2000 Lexus GS400 with 84k and i recently noticed it wasn't as fast as it was and hesitates sometimes while im accelerating. Then my check engine light came on and so did my (TSC)Traction control. The diagonostic gave me check engine code P0121 which is TPS/PEDAL POSITION SENSOR A CKT RANGE PERFORMANCE. Anybody have this problem before??!