98 Tahoe engine light

[Landchipper]

I was able to get the codes checked and it was the heated O2 sensors and after replacing them all is well. My question is how do I turn it off to make sure that those items were the only problem? Is there a way that I can do it? Or do I have to pay the dealer to do it?
Thanks for your help,

 

[FunFordCobra]

To reset the ecm... On mine, I just disconnect the negitive for 2 to 5 minutes.

 

[Landchipper]

Will that have any effect on other electronics that are not grounded independently?