From my manual.
-- HO2S-11 = DTCs P1131, P1132 and P1130
-- HO2S-21 = DTCs P1151, P1152 and P1150
Possible causes:
Fuel system
-- Excessive fuel pressure.
-- Leaking fuel injector(s).
-- Leaking fuel pressure regulator.
-- Low fuel pressure.
-- Contaminated injector(s)
Induction system
-- Air leaks after the MAF.
-- Vacuum leaks.
-- Restricted air inlet. don't think so now!
-- PCV system.
-- Fuel purge system.
-- Improperly seated dip stick. WTF! 
EGR
-- Leaking gasket.
-- Stuck open EGR valve.
-- Leaking diaphragm.
Base engine
-- Oil overfill.
-- Cam timing.
-- Cylinder compression.
-- Exhaust leaks before or near the HO2Ss.
l Check air intake for leaks, obstructions and damage.
l Check air filter, air filter housing for blockage.
l Verify integrity of the PCV system.
l Check for vacuum leaks.
Last edited by chongo; 04/19/04 01:42 AM.
1996 2.5LT V6 Contour ATX
My Tour+help/info pics
E0 rims, Gutted Pre-Cats,CTA Custom Exhaust & Intake, Diablo Chip.
