Bizarre Cam sensor behavior

[Tmn8tr]

I have been chasing a random stumbling/rough idle issue ever since I purchased my Hellblazer a year ago. I thought I had it narrowed down earlier this month when I purchased and installed a new FPR (I am getting really good at dropping the gas tank.)
On a family road trip I started noticing a drop in power momentarily at highway speeds, but below 2500 RPM. I figured it might be the CPS, and picked up the cheapest new one I could find (Chinanono brand). Bam! problem solved, but now we have a check engine light/code saying 'Fault in CPS circuit A/bank A. I'm not surprised due to the Chinese origin of the part and vow to buy Delco once I'm back in the comfort of my own town. once back I go out and get a Delco and swap them out, but now the problem is back but the light is off and there are no codes stored. What am I missing? My wife is annoyed to the point she doesn't even want to ride in it anymore.
Aside from the ECM I can't think of anything that would make it behave this way.

Thanks,
Tim

 

[The_Roadie]

Flaky wiring, nicked insulation, a connector at the PCM that has to be unplugged and replugged to clean up the contacts?

What was the precise code again?

 

[Tmn8tr]

Thanks Roadie!
It was P0340 I believe, I tossed the piece of paper I wrote it down on, after I switched back to the OE part. I inspected the CPAS plug and wiring and it seems to be fine (not loose at all), but I haven't looked sideways at the PCM.
T>

 

[Enderbygrandpa]

I was having idle problem would almost stall. turns out had low Freon in air conditioner added can of Freon problem went away as I was filling.