i am doing a S5 to S4 swap...i was wondering what i have to do about the bac valve? and why are there 5 solenoid valves on the S5, and only 4 on the S4? i was wanting a quick cheap fix until i can do the one with the tire pump.....also i was told i have to change my injectors...but i dont know which is primary and which is secondary. also...am i just supposed to change the TB...? thanx in advance

 

also....my S4 is an 88 gtu...and my S5 is a 91 gxl....thanx

 

Models do not matter. There is only turbo or nonturbo, s4 and s5, 4 distinct engines. Question answered via email.

Boy, I sure dont look forward to seeing all your posts about this swap in the next 2 weeks.