1-9 means that your RCM (airbag module) needs to either be cleared or replaced. I had to go through the same thing when my airbags deployed.
The 4-6 can either be low resistance over the passenger or driver side pretensioner, you have to hook up to a scan tool to determine which. A tuner won't do it for you, I've tried. Most likely they are both going to have to be changed out. New from Ford, you're looking at around $200. Your best bet is to check out ebay, sometimes they have an RCM and two pretensioners being sold together.
2004 Ford Ranger Edge manual 4.0 4x4 with 3" Body lift, 33x12.5 BFG A/T KO's, on Eagle Alloy 057 rims, and alot of mods
2011 Ford Mustang GT 5.0 manual with no mods yet
2005 Ford F250 automatic 5.4 4x4 with no mods