Found a small knob object on the driver side floor board. Any help? I've attached images.

 

It goes under the gas pedal. I'm 'fairly certain' it was adjusted to a predetermined value using a scantool to prevent either overly opening the throttle blade and/or preventing throttle cable from stretching. The previous models 95'-97' X300
(other years/models also) used this same setup with the exception that it had a transmission kick down switch built into it. Yours is just an adjustable stopper basically.

 

That is the head off of the Kick Down Switch. I have attached a scan of the tech manual showing it's location.