I loved my daughter's 05 (automatic) I bought her so, I found an 04 (std 5sp) in great condition for myself. Both run great.  Both start without issue but sound like the battery is low or "tired".  Both new batteries. No "Check Engine" light.  New Ancel AD410 code reader for my birthday--thanks for talking about it, Scotty. I got curious and decided to see if there are any cods to read. Both cars have same codes--P1518--Starter switch circuit low input;  P0519-- Idle Air Control System Performance.  I cleared the codes and they come back. So, it is current feedback. I have test driven several Foresters in this vintage and they all sound "tired" when they start but start every time. Vac hoses all feel good and I cant find any leaks. Electrical connections seem solid and no wire or connection breaks/corrosion. I'll get some Mass Airflow Sensor cleaner to clean both. Any other ideas? And are they related?  Meaning, if I fix P1518 will P0519 just go away?

Many thanks, in advance.