IS THERE ANY COST WITH CHECK ENGINE LIGHT?

While most shops will turn the check engine light off by clearing the code or codes in the computer, if the shop that did the repair is not the one that diagnosed the problem, why would we expect them to diagnose and repair a second time at no charge? Shouldn't we hold whoever diagnosed it the first time responsible for that? Your question is a little vaque, need more info...

Resetting the engine computer and clearing the trouble codes should absolutely be a part of the repair. In fact, if after the new sensors are replaced and the shop tells you it's fixed, if the light is not off or the light comes back on, return to the shop and have them take care of it. The complete repair should allow the light to be turned off and for it to stay off.

Most repair shops will charge a fee to retrieve trouble codes from your car's computer (some parts stores will do this for free as they hope to sell you parts to fix the reason why the Check Engine light came on in the first place). Repair shops will check the Oxygen sensor heater circuit, and check the sensor performance before just replacing the part and will charge a diagnostic fee for testing the component. If they replace the component they will erase the code (turn off the light) and test drive the car to verify they have correctly carried out the repair. Turning out the light is included as part of the repair.