[Hydro]

Running a click test and listening closely to the injectors may give some hints -- if all the failures are on one bank, ...well

ForScan would be tool of choice

Also checking at the IDM connector for failures would be where I would start -- if you see a failure then proceed to the next connector and test again -- oftentimes "messing" with the connectors will mask a problem -- so a methodical approach is my goto

 

[Hydro]

Sounds like it could be heat related in the IDM -- did you check it for water damage?