1996 GMC Sierra 1500 - Flashing CEL, High idle and stalls after cold s

[Bader99]

I've searched everywhere for an answer and can't seem to find one. The CEL flashes when I take my foot off the throttle. When I cold start it will go above 2000 rpm and then stall. While driving the truck wants to take off and I'm constantly on the brake trying to keep it under the speed limit. It also hesitates when I initially press on the gas. I've heard that a flashing CEL is a misfire but I don't have a misfire code and it doesn't sound or feel like it's misfiring, could it be flashimg from anything else? It does have two codes which come and go: one for the iac and one for the tps. I replaced the iac a week ago. Just ordered a new tps but haven't gotten it yet. However, with the scan tool hooked up it seems to be functioning correctly, smoothly goes from 0 to 100%. So my questionschedule are:

* Could a faulty tps cause all of this or what else could be wrong with it?

* Could a tps be faulty even if it appears to be operating correctly on the scan tool?

* What are possible causes of a flashing CEL?

* Am I missing something?

 

I am a huge fan of these forums but a first time poster here. Thanks in advance for any help, I really appreciate it!