I'm stuck on the dual TPS?? Have I missed something??? That aside ... it's a enthusiast forum and near as I can tell ... the best way to tick people off is to proclaim that "this" choice sucks whatever "this" may be??
Intermit "issues" are some of the worst problems to deal with. And those can happen to anything that has "moving parts and interrelated components" so ... pick your brand and there is somebody out there ... with the same issue.
Folks are "trying" to advise ... you to stop doing what your doing ... "change this change that" and hopefully the "issue" will go away??? Sometimes that work ... sometimes ... not so much???
For all you know ...one of the components, you've already replaced was a bad unit??? "Apparently" ... that can happen??? First hand recent experiance on that one, on my 951 with a bad pump with not one but two bad fuel pumps??? I refused to belive the newly installed fuel pressure gauge ... which refused to budge past zero??? Spent about a month trouble shooting everything! Till I got back to the fuel pump??? So yeah ... crap happens!
What you could do first is grab a DVOM and A Chilton or Haynes Manual or of course a factory manual and start to trouble shoot all the sensors and see it they are in spect?? "If" they all check out in spec and you still have issues ... then getting into a "Pro" would be the next option.
And if you are going to check the sensors and stuff, take a close look at the wires for the connectors for cracks and stuff. I'd used WD40 and silicon grease on everything you disconnect and reconnect.
And the TPS .. don't know about the dual thing?? But as I understand it on GM's there should be a yellow wire in there somewhere and that wires should always read 5 volts?? If it does not that points to the ECU. LLot's of work but it's a plan if checking sensors out first does not pin point an issue then perhaps another set of eyes, some dollars spent and a Snap Tool will??