oh, well, civics and sentras are similar, yet different, cause see, ill tell you what it looks like.. if you remove the stock manifold, there is 2 things.. there isnt enough room, to simply lift the car, and place them straight in from above, becuase its a 1 peice design. Second, there is the front motor mount. (ithink) and a big black bar that blocks a straight push in from underneath, i think you can unbolt this, im not sure, i have to look