[padgett]

Personally, I'd be looking for a wiring fault. P000D seems to be a fairly coarse code " If the PCM detects an open, a short to ground, or a short to voltage" and if you changed the phasers that leaves the wiring or the PCM. Since it is erratic, I'd be looking for a nicked or frayed wire or a marginal/loose connector.

Does the code set if you unplug the phaser ?

 

[padgett]

If the head is the problem, shouldn't it be getting a P030x (usu. p0302 or p0304 sometimes P0300 - misfire)