I am getting A P-1690, P-1694, and P1693. I know the 1693 ends up being the Maps sensor. I replaced it about a month ago. The 1690 is a communications error between the injector pump sensor and the engine sensor. There are a lot of variables to consider when reading possible fixes. Is there a most common problem I can start with before heading to the injector pump with this? Thanks in advance for all help.

 

I'd start with checking all connections from the battery's making sure they're good, clean and tight. Find all the frame/body grounds, clean those and double check connections in the areas you were working making sure they didn't come apart or forgotten to be reconnected