I just bought my 1992 Bronco with 113,000 miles.
The first day I was driving it the "check engine" light would come on but then go out after a minute or two. I returned the truck to the dealer (Used car dealer) NOT FORD DEALER!
He put it on the scanner and came up with a conflicting code. In other words he said the trucks computer was looking for TWO O2 sensors.
He did test the O2 sensor and it tested fine.
My truck has only one O2 sensor. Has anyone heard of this before?
I was thinking maybe the O2 computer on the truck is bad and thats why it doesn't know there isnt two sensors.
Please help
Thank you in advance.
Jon
Oh one more thing the mechanic said was to call a local Ford dealer and ask them if any "silent recalls came in about this problem"

 

Your Ford is equipeed with a dual function O2 sensor. One function is of coarse the oxygen count function,the other is the sensor heater. You will have either 3 or 4 wires on such an O2 sensor.Here is a tip,there are 2 disconnect points in the harness for the O2 which can give you trouble if corrosion/water gets in them. of coarse as at the sensor,the other is up on the firewall near the A/C evaperator box. Flush out both with electro-clean and put a 'lil dielectric compound in there. Finally, if the exhaust has been modified on this truck, it is possible that the downstream O2 sensors have been removed and the harness taped back into the wire loom !
Phillip

 

I have a 94 with the same problem. The warmer the weather the more my check engine light comes on. I have replaced my O2 Sensor. It's easy to do. And will save you some coin. I have also replaced my MAP sensor, Cleaned my injectors, and taken it to two mechanics that can't find the problem. My exhaust also smells funny. It is not the Cat. converter because the O2 sensor is reading the exhaust before it enters it. What have you found out or done so far. Email me if you would at elsfarm@core.com. Thanks

 

yo..here is a www site for eec-iv codes:
http://dalidesign.com/hbook/eectest.html

111 System checks OK

here is what is listed for oxy sensors there...
171 (M) Oxygen sensor not switching - system was at adaptive limits - Single, Right or Rear HO2S - Fuel control


172 (R,M) Oxygen sensor not switching - system is or was lean - Single, Right or Rear HO2S - Fuel control


173 (R,M) Oxygen sensor not switching - system is or was rich - Single, Right or Rear HO2S - Fuel control


174 (M) Oxygen sensor was slow in switching Single, Right or Rear HO2S - Fuel control


175 (M) Oxygen sensor not switching - system was at adaptive limits - Left or Front HO2S - Fuel control


176 (M) Oxygen sensor not switching - system is or was lean Left or Front HO2S - Fuel control


177 (M) Oxygen sensor not switching - system was rich Left or Front HO2S - Fuel control


178 (M) Oxygen sensor was slow in switching Left or Front HO2S - Fuel control
and at times, the sensor can be damaged by a non-O2 sensor safe silicone used for a gasket seal, or an over rich fuel condition ( I think)...
good luck, Al