i have se saloon 2004 automatic and i want to get a CNG kit installed in it. can any frnd tell me what things are necessary for it i mean i read all advertisment about CNG gadgets like turbo chips etc etc...... can some friend put soem light what things are needed for an EFI engine conversion to CNG and its smooth running ..... and how CNG effects the engine i mean if i switch back to petrol does CNG settings effect normal engine running on petrol?.... also whats is this emulator? thanks