Alright so I got a Microtech LT8-S with a harness and all. I actually purchased it from $100T2 My question is, "What can I get rid of like sensors and what not" The AFM, Pressure sensor... "Can I get rid of the stock harness? Do I need to keep anything from it?" I have S4 TII...

 

Get rid of the passenger side engine harness, but keep the drivers side. That's where your alternator wiring is and etc.

When you remove the engine wiring harness, be sure to keep the windshield wiper harness, it is bundled in there. You need to take that harness out, and keep it installed on the car or else you will have no wipers.

You can ditch the afm, boost sensor, and emissions.
If you want to use the LT8-s' internal map sensor, go for it.
You'll need the water temp sensor, air temp sensor, cas, and TPS iirc.

If you have the blue microtech manual, just follow the directions and you'll get most of it done pretty easy.