Oil catch cans are they needed?

I installed the Ford Performance ones on both sides.

My car came with the FP oil catcher on the passenger side. I had pulled the hose off the drivers side and there was oil in the hose. I installed the FP on the drivers side since this hose dumps into the intake. My two cents.

Ray

I did the JLT ones on both sides. Thee is always some oil in the passenger side. Have yet to find any on the drivers side. Driven on the street regularly plus track days.

Passenger side - JLT brand unscrews easily from the bottom and pour out the bad stuff.