P1605, P1604 - No CEL, known issues

Hi folks! My “fun” ‘17 is striking again (maybe). Overall my truck has been running really well. I do have the timing cover “seep” I plan to get resolved when I’m ready for another oil change (I bought the extended warranty to 100k which should cover this extensive repair). But this issue isn’t an urgent concern to me as I’m not measuring any oil loss on the dipstick between oil changes (which I’ve always done prematurely at 5-6k).

However, yesterday I decided to hook up OBD Fusion and see that I have two current codes P1605; and P1604. Seems these codes could be anything from faulty ECM to TCM to wiring to fuel pump or even fuel quality. What it hasn’t done that I’m aware of is stall/die on me or fail to start which these codes also can indicate.

Anyone else had experience on your trucks with these codes and diagnosed or repaired? I know it’s possible they are just sensitive codes and may well require other data to trigger a CEL and thus they may just clear themselves and with no scanner I would be none the wiser however given my experiences with my “Friday” truck I don’t want to assume...

 

And I know one thing I need to do is look at the freeze-frame data from Techstream which I can do, just haven't had time to lug out the old laptop that has TIS on it to read the data, but I will soon.