Laurens, if you installed a new cable did you thoroughly clean the pedal area so the pedal can return to zero?
The TPS unit seems to be a culprit and another place to look but as Bluebricked said it can be adjusted. It can be adjusted without the S&S software but it is more accurate that way.
You shouldn't really try adjusting the TPS without Protune - its so delicate in its setting - go a micro millimeter too far and it will not run correctly. As Callum states with a voltmeter it can be done but easier with Protune. Also make sure engine up to temperature when you adjust it...finger burning time as the little screws are so difficult to get to.
And if you have a later TPS its non adjustable - unless you remove TPS and carefully elongate the fixed position holes to allow it to turn.
