What are the major changes you have to make to have a 2006 GTI accept a TSI engine? Is it manly wiring and a computer or is it more in depth. Also does the transmission from the FSI mate with the TSI. Only reason im looking into this is because i recently purchased my GTI and it has some major problems. Plastic broke off from some where and got into the pick up tube and starved the engine of oil. The cylinder head is ruined but surprisingly the rest of the engine is fine. I was looking into the price of cylinder heads and realizing for about 1000 more i could get a used TSI engine. Any thoughts would be greatly appreciated.