No they cannot be cleaned and neither can the convertors. With catalyst codes check for any exhaust leaks upstream of the O2 sensors. Check the fuel trims and make sure they are not making more than a 15% total correction. Have someone pull the current software level in the PCM and check for updates. The last thing you can check is the O2 sensors for maximum and minimum voltages and the length of time that it takes to switch from rich to lean, and from lean to rich. If all of that checks out then you will be facing replacing the catalysts.