How long before the computer reset.completly after replacement of a bad sensor on 2009 Chevrolet Cobalt

I had a bad sensor trying to hace car insoected.replaced part now i have driven tomwo hundred miles and evap semsor and another are still not ready

Asked by for the 2009 Chevrolet Cobalt
Would you please have someone please print the question so we can understand what you have.
Sorry for check engine light was on my emissions inspection is due.diagnostic.i had bad sensor had it replaced....mechanic said drive 100miles or so so computr will reset ..its been 3days...250.miles.and evap and oc sensor still not ready.
Your "mechanic" is wrong. Take the vehicle to someone who has a real scan tool to look at data stream and clear codes.
My mechanic is not wrong ive been to his shop for many years.his scanner is up to date. I got in contact with chevy.and they said drive for about a week..use all control heater ac..erc..etc..and it should reset by then
I don't care how long you have been going to this "mechanic", find another one.
A real enhanced scanner will be able to read serial data and trouble codes. I suspect your "mechanic" doesn't know how to use "his scanner". Good luck