There IS a paperclip method, though I cant tell you how to do it... something with bubble gum and a volt meter or something... 
you can get a simple code reader for about 30 bucks at WALMART and it beeps and flashes lights at you... or you can go all out and get one that displays the codes on an LCD....
I did a search and found this... might be helpful
http://forums.mustangworks.com/showt...per+clip+codes
__________________
'89 GT Convertible:
TFS TW Heads, TFS Street Intake, TFS Stage 1 Cam, FMS 1.6 RRs, 24# Injectors, Pro-M 75mm MAF, No Name CAI, 3.73s, O/R H-Pipe, FlowMasters, AOD w/ Trans-Go Shift Kit
|