Hello, I'm Jason. I will do my best to answer your question quickly and accurately using the information you have provided.
There are two common reasons for these codes, which are long term lean fuel trim codes for each bank of cylinders
Now, in a number of cars, the air mass meter is often at fault, but since the 360 has two of them, I doubt seriously that both failed at the same time
which leads me to think that we're dealing with an unmetered air leak, or vacuum/intake leak
the best way to determine the source is to have the intake system tested using a pressurized smoke generator
most good European independent shops will have one of these, and it makes finding intake leaks very easy, as you just pinpoint the area where the smoke is escaping