2001 C240 45K Miles

Removed top covers, saw breathers and valve cover have unusually large leaks for this mileage. Clearly leaking into plug wells on both sides.
Replaced covers,
Removed oil cap (clean, not milky) and radiator expansion tank cap, started car. I want to see if anything is churning and bubbling. All is well, re-capped both.
A short roady
Hooked up iCarsoft and No engine codes.
Another short highway roady and it threw a CEL and bad idle.
By now I am not around and so I don't have a code reader.
Could any of this have caused this issue? If not could it be that the leaks caught up with it?