TPS issue?
 

I have a 2009 5 with 2.3L gas. Every now and then I experience the same symptom with the accelerator pedal going to the floor with vehicle barely moving. Code comes up as Throttle Position Sensor low current. The shop cleared the code and vehicle runs and drives normally, for awhile. When the problem arises it is accompanied by a "CLUNK" and then the check engine light solid. Supposedly the TPS on the throttle body checks good, but also supposedly there are a pair of sensors attached to the throttle pedal (image on parts computer at parts store) but I can find only one wire plug at the pedal. Anyone else ever experience this issue and what did you do to fix it? I don't want to keep buying parts and installing them only to have the problem reoccur. Any help here would be appreciated.