>>131551
>Is there a list of polyunsaturated fat containing foods somewhere
Yes, but because they can come from diverse sources, it is always best to consult nutrition databases. The main sources are vegetable oils such as corn oil, soybean oil, canola oil, flaxseed oil, peanut oil, sunflower oil, cottonseed oil, etc, fatty fish and fish oil, nuts and seeds.
This table will show some comparisons:
https://en.wikipedia.org/wiki/Vegetable_oil#Composition_of_fats
Note that coconut oil is listed as a "vegetable" oil, but of all the fats, coconut oil is among the most preferred for health benefits because it is so highly saturated with very little polyunsaturated fat content.
>>131551
>or will I have to examine everything I plan on eating?
It's not an either or matter. If one actually wants to successfully avoid polyunsaturated fats consistently, there is no choice but to both be aware of the main sources and inspect the ingredients of everything eaten.