when you say it won't idle... how does it not idle, does it surge or idle low and stall, does it blow black smoke? does it stutter under boost? have you got any codes?
jumper with a piece of wire t & e1 in diag box, jump in car, turn key to ign and count the codes from engine check light
example code
21
flash flash... flash
34
flash flash flash... flash flash flash flash
2 codes stored
14 & 52
flash...flash flash flash flash............. flash flash flash flash flash... flash flash
let us know what codes you get