Cant seem to find anything on code ecm4300 my scanner says its a fuel tank leakage issue mainly just looking for info on that.. but if anyone has any other ideas on the rest of these problems thatd also be appreciated got ecm 1300 popping up for a issue with the maf sensor ive had the car parked for awhile trying to decide what to do with it because i was pretty sure it had a bad piston ring still havent done the compression test after finding what looked like oil on a sparkplug robertdiy said it was probably dried up unburnt fuel but idk it definately looked like oil to me so i just parked the car but took it for a drive today and finally got some codes to pop up and go off of so maybe it is just a air or fuel issue like i originally thought dont see any clear fuel leaks .. 2000 s70 glt se

 

For an evap leak - the easiest way to find them is with a smoke test - it's a tool that makes smoke, you T into the evap system vacuum lines and watch where the smoke leaks out - anything from a broken vacuum line, stuck open purge valve, a bad seal on the gas cap -

Air mass code - intake air leaks between the AMM and the O2 sensor can cause that although I have replaced hundreds of bad Air mass meters with that part number.1275749 - So many still have the number memorized!