Sup guys. I got Fault code P2128 Throttle/Pedal Position Sensor/Switch “E” Circuit High Input. It Happened at full throttle. Stock ECU with a TBE and ported wastegate. I did perform a search and came up with nothing. Has anyone come across this fault before? does anyone know if the STi is suppose to have a throttle stop? Any help would be appreciated.

 

I got this same code on my 100% stock STI. It means that whatever sensor is responding to the angle of the throttle pedal is getting a reading of more than 100%. Somehow I cracked the throttle stop that is screwed into the carpet and it fell out. Subsequently my throttle pedal travelled too far causing this engine code to pop up. I have heard of this condition occurring with an STI at a track event with low fuel. My tank was full. I assume that symptom was the same yet the code would be different. In any case I will find out if a new throttle stop will fix this condition.

 

yeah it has happened three times in the recent month. all times with over 3/4 tank of gas, in a straight line. but after looking, i am not missing one at it seems fine. did you take your car into the dealer? if so what did they say? or did you just replace it and clear the code.

 

I'm replacing the stop tomorrow and considering going to the Wed Nite drags at Sears Point to check out if this fixes the problem. Will keep you posted. Fingers crossed.

 

From what I have heard, when that happens you are getting what is know as boost creep.

Here is a link for more information.
https://www.i-club.com/forums/engine-power-ej25t-sti-2006-wrx-90/why-did-do-boost-creep-44825/

 

No... mine was NOT boost creep. it was a loose terminal in the wiring harness near the gas pedal. fixed now