can someone help

Hi
I had a cat put on my 99 camaro and then my check engine soon came on so I hade a oxygen sensor put on and the light went out but when I connect the OBD11 code reader to the car all the code were gone but 2 of the monitor icons were flashing can someone tell me what it means. one was the C monitor icons and one was the O monitor icons.

Thank you :rofl:
ihatemycar45

i dont kno anything about that, your best bet is to google it and see what you can dig up.

good luck:smokin:

Thank you