[tomk]

Inspect and reseat all the connections at the PCM?

 

[tomk]

With intermittent problems like that, my first guess would be corroded or otherwise damaged connectors or wiring. particularly near the PCM connectors.

It isn't likely that you'd all of a sudden have multiple injectors going bad.

I don't think the fault code is actually "open". it should be just a generic injector control-circuit failure (the OBD reader you're using might be mistranslating the code.) These codes are set when the PCM doesn't sense an inductive 'kick' when de-energizing an injector. the lack of kick can be due to either shorts or opens.

If a careful check of the connections at the PCM shows nothing, it's possible that you have a bad PCM.

?tom