If you use a code reader to clear codes, the light will go off and the history is gone. If you do the fuse thing or battery cable, the light goes out, bit the code stays in history. If the light goes off because the problem resolves itelf after so many drive cycles, it will stay in history also. I have tried it and that is how it worked. The CEL will come back on regardless of how you got it to go out if the problem still exists.