I’m a rising junior, and I was thinking about dropping Spanish for the remainder of my high school career. My sophomore year I finished Spanish 3, which fulfills the requirement. Most colleges I’m looking at mention 3-4 years of foreign language (engineering), but since I finished level 3, that would count as 3 years, right?
I was originally planning on taking it for another year but I honestly don’t really like the subject. Since I’m taking some other difficult courses, I feel like it would be too much to handle junior year, especially with standardized testing and other stuff going on.
Is this a good/bad idea?
Bad, I would challenge yourself and do more, colleges like to see that, and I doubt it would be hard if you already have done it for three years. 
If you aren’t interested in the subject, don’t take any more. 3 years is more than the majority of students in the US. I’ll be stopping after Spanish 3, definitely. I’m just not good at it like I am with other subjects. Pursue what you want to pursue, not what you think colleges want to see.
And @writer80 , trust me, three years of language does not make it easier at all, especially if you have crappy teachers all those years (like I did). I can’t carry a simple conversation in Spanish, even after 3 years of learning it and a Spanish speaking parent.
Look at some of the colleges you are thinking about and see what they recommend just to make sure.
I would recommend through Spanish 4 if you can.
Unless you want to attend an Ivy League, taking 4+ years of a foreign language really isn’t necessary. If you have other interests that you’d rather pursue in classes, go with them. Level 3 is a good level to reach.
I am sorry you didn’t have the best experience in Spanish! @Shanban1607 but I am not sure if the OP had the same experience