What motor/year are you dealing with?
Symptoms of a Bad or Failing Throttle Position Sensor:
Car won't accelerate, lacks power when accelerating, or accelerates itself. ...
Engine won't idle smoothly, idles too slowly, or stalls. ...
Car accelerates, but won't exceed a relatively low speed, or shift up. ...
Check Engine Light comes on, accompanied by any of the above behaviors.
Thats all from google.
Grab a mulitmeter and go test yours, that will tell you if its bad.
Read this:
Toyota 22RE Throttle Position Sensor
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92 ExtraCab on 38s: built for go, not for show
88 4runner: Solid axle, doubler, fun stuff
IG: rattlewagon
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