How will a B in AP Calc impact pursuing engineering/CS?

From which university?

Santa Clara University. They have a well regarded engineering program. This kid graduated from college in 2010.

I’m going to be frank and say that IMO it depends on the school. Some of the more technically focused programs do say that they focus on STEM grades on a HS transcript. Others will be more forgiving.

I also agree that if you can get a 5 on the AP, the class grade will matter less. Hopefully the exam went well for you!

That all said, I wouldn’t lose sleep over it. Reaches are reaches even if you had a perfect GPA. Build your list realistically for your safeties and matches and you will be fine!