Just curious,is it always necessary to clear codes manually or if you remedy a problem willthe codes clear over time/miles

for example i just changed an O2 sensor. Think i read the code would clear itself shortly,or should i clear it after replacing the part

thanks

Some codes will clear over time, but personally I would clear it if you have access to software to do so. 

2 hours ago, Gizmo said:

Some codes will clear over time, but personally I would clear it if you have access to software to do so. 

Thanks for that. Have an OBD gadget so will clear and see