Service Manual Codes
 

Anyone know what P1123 and P1125 stands for? Any help would be greatly appreciated.

The O2 sensors are detecting a rich mixture condition and the the DME is compensating but has reached it's trim limits... as I understand it. Make sure your air filter is clean and clean or replace your MAF sensor. Then clear your codes and see if you fixed it.

Thanks! Pardon my ignorance but is this a serious or minor problem?

Minor. You are burning too much fuel. Over a long period it may foul your plugs, carbon your heads and foul your cats, but not today. You should fix it soon though..