If its acting abnormally, most of the time you will get a DTC/CEL. I wouldn't just start replacing things...that can get expensive.

It sounds like a vacuum leak to me. With a bad cam sensor the car wont run. Or will just shut off at random. Easy way to test for leaks is to get some starter fluid and spray it at all the areas that it might be leaking while the car is running. If there is a leak it will suck the starter fluid in and you will hear the engine accelerate a little bit.

You could try calibrating the TPS I guess...there is a test for resistance across pins 1+2 iirc...you probably wanna search tuners for that though. And I believe pin 3+4 will have continuity when its at "closed" or 0%. Easiest way to set it IMO is to loosen the screws on the TPS and and rotate it till you get continuity btwn 3+4 while the pedal is at rest. Then stick something real thin like maybe a credit card or whatever (small feeler gauges are best if you have em) between the pedal and the stop, to hold it as if you were just barely touching the pedal. At this point you want adjust the TPS until pins 3+4 are open. Then when you pull the card/feeler out it should show a closed circuit again.

Could also be a dying o2 sensor. Or a big exhaust leak. Who knows.