What loom sections required for 20v conversion

I've started stripping out the loom from my 1.8 sun TT. I've got out the ecu and two sections of loom that go to it. However? I had to disconnect one from the small fuse box section with the big fuses in to separate it from other sections of loom (the braking one which goes into the passenger side). Do I need any of that loom to proceed or can I let that go with the car? Tia