PFM006 likely from liquid damage, or possibly accidental damage if someone replaced their own battery (it is not easy to replace the battery on the non-Touchbar 2016-2017 models). The article I'm linking mentions a possibility of the Trackpad or ALS sensor/camera.
https://logi.wiki/index.php?title=Apple_Hardware_Test_(AHT)_and_Apple_Diagnostics_(AD)_Codes#:~:text=PFM006
The PPN001 seems to be a power adapter issue....is the power adapter connected when running the diagnostic?
The slowness is most likely a power related issue which is reinforced by the diagnostic error.....either the new battery is bad, or possibly a cable is not connected (or a cable or connector has been damaged). The battery cable & connector for the battery flex cable is very easy to pull loose or even damage.
If this is a third party battery, then there is a very high chance the battery may be bad. The quality of most Lithium batteries is extremely poor even when purchased from a respected vendor such as OWC or iFixIt.
If this is an Apple or AASP repair, then take the laptop back & have them make things right since you have a 90 day part/repair warranty depending on how Apple or the AASP performed the repair.