You will have to install a catalytic converter to get the light to go off.
You may have a different code, the computer may not have been reset, the converter may not have been installed correctly, problem may not have been the converter in the first place.
A failed catalytic converter is one of hundreds of parts that can cause the check engine light to be on.
Disconnect the negative battery cable for 5 minutes. If that does not reset the Check Engine light you will need access to an OBD2 scan tool.
Cleaning a catalytic converter to reset an error code is only a temporary solution for a 1999 Grand Am SE. To clean the catalytic converter in this case you would need to gently blow out any build up with an air compressor. You would also need to replace or clean the oxygen sensor as well or the code will not reset.
This is a reminder light to tell you to remove the pellets from the catalytic converter, clean them, and put them back in. Yes, there is a reset button. You can safely ignore this light.
You cannot reset an O2 sensor, you can replace them though they are located on the exhaust pipe before and after the catalytic converter. You can then reset the computer with a scan tool but if the problem is fixed the light will go out on its own after a while.
catalytic converter
This light is indicating a emissions problem or failure. The catalytic converter may be operating at low efficiency which is a sign of failure.
Legally you can only replace a catalytic converter with another catalytic converter.
Check engine light, low power, poor fuel economy, highly illegal to run without the catalytic converter.Check engine light, low power, poor fuel economy, highly illegal to run without the catalytic converter.
You can't.