Recently my engine light came on and the car has been chugging a bit. First noticed it on inclines but now almost constant. Popped my hood and saw what appears to be a broken or cracked line. Arrow on the picture (2001 picture, not my actual car) points to the piece in question. 1st, what is it? 2nd, could this be the culprit? 3rd, easy to replace? Thanks for your help!