Did you already check out the TSB below?
2002 Ford Escape Electrical System Service Bulletin 118546
NHTSA: Action Number: 10004894 Service Bulletin Number: 118546
Oct 04, 2004Component:
Summary: Airbag lamp illuminated and diagnostic trouble codes (dtcs) b1877 (driver pretensioner circuit open) or b1881 (passenger pretensioner circuit open). *tt this bulletin supersedes tsb 03-20-11 dated 2003. *tt
2002 Ford Escape Engine And Engine Cooling Service Bulletin 320498
NHTSA: Action Number: 10008205 Service Bulletin Number: 320498
Jan 01, 2004Component:
Engine And Engine Cooling
Summary: Driveability-intermittent engine quit or idle dip-no diagnostic trouble codes (dtcs) present-vehicles equipped with 3. 0l duratec engine only. *mj
Spoon Sports 7/12/2011take the IAC out and clean with carb cleaner,they will get carbon build up in them,DONT push or pull the plunger looking thing when it is out spray it good then spray a little WD40 in it reinstall ,you will have to unhook battery to clear computer,do this first install IAC plug the plugin back into it reconnect battery crank,let it idle a few minutes for computer to relearn IAC or you may have a bad TPS.