I had the check engine come on and gave me code u0073 and p0300 I was trying to see if u0073 could cause p0300
The U0073 code indicates an issue with the CAN system. Here is some info for you.
U0073 GMC - Control Module Communication Bus OFFRead more: https://kvjournal.ru/u0073_gmc.html
The P0030 indicates an issue with the O2 sensor. HEre is some info for you.
P0030 GMC - HO2S Heater Control Circuit Bank 1 Sensor 1Read more: https://kvjournal.ru/p0030_gmc.html