My guess, the problem is fixed and the check engine light will go off eventually, sooner rather than later probably. Options for the pesky warning light are
- wait, hope it turns off
- ask shop to turn it off w/the scan tool, and take it back to shop if it turns back on
- ask shop to measure the pre-cat & post cat O2 sensor signals with their scan tool to verify both sensors are behaving correctly. (This is a standard test, used to determine if the cat is working or not.)
One heads-up, if the warning light is turned off using a scan tool, while it will turn off the check engine light, it will also place at least one emission system’s readiness monitors into the “not-ready” state, and may prevent the car from passing an emissions test.