1990 760 turbo No amtter what I do I get a constant reading of 8 and 9 off the o2 sensor. I have checked everything I have tried to make it run lean by vacum leaks but still no change. I checked the fpr and its fine bypass return hose pours fuel out when running as it should, coolant temp sensor has been checked twice with an ohm meter and works great, thermostat opens fine, changed cat now probably full of soot, changed o2 sensor still engine light on and o2 reading 8 and 9 which is full rich. checked control unit at terminal 13 and 5 and i get volts around 5 or 6 which is fine, cleaned out TB and is fine, it runs great and smooth but will not pass Cal. emissions email me at ufarley@earthlink.net Thank you.