You will need your O2 sensors to be plugged in. If you got a header that doesnt have a spot for the O2 sensor, dont use it. Depending on how bad your crack is, you could probably just take it to a muffler shop and have them weld it up for cheap.
mine was cracked also.. but for what they were gonna charge me to get it welded i got a header for the same amount.. go to a shop and get a quote someone may hook you up
The header that you bought will still work, it bolts right up to the factory downpipe that has the cat converter on it. If you want aftermarket exhaust from the header all the way back to the muffler, you will have to buy an aftermarket downpipe.
Does anyone know if the headers on ebay are worth it? Since d17's don't get much wouldn't it be fine to get some 40 dollar headers? it's all simple piping right. or does anyone know if the quality is that crappy/