This is a difficult question to answer, because there are so many variables. So let me answer it in a nuanced manner.
If your ethical antennae are up, then you will surely notice more ethical issues. In fact, you will be surprised at how many things you will see. When you look for something, you tend to find it. Moreover, this will take up more of your time. Observing things takes a lot of time and energy. Now all of this can take away from the work that you are paid to do. If this is so, then you will surely please your boss less, because what he/she wants is excellence from you.
If we change the scenario, then pleasing your boss may be very compatible with ethical observations. For example, if there is serious ethical wrongdoing that is hurting the business or can hurt the company in the future, then detecting this breech in ethics might help the company greatly. In this case, pleasing your boss is very much compatible with having your ethical antennae up.
From these perspectives, what is most important in determining the answer to your question is the context.