hm i'll keep that in mind. does anyone have any links where i can read up on this.. like an AEM forum? I'd like to find people with mustangs who run them and are fluent in using them so i have a good idea of what i'm doing before i get started. From what you say i should be pretty happy with the change which is what i'm looking for. my idle has never been like stock or even close. i've always had an obscure idle. my WOT is great, but my pt. throttle really lacks in spots with the pms it seems. How much are these new, and is it better to buy new, or should i get a used one? and where and how much are they?