I recently found out that there are two different O2 sensors specified by Ford for the 87-93 model year Mustangs. It appears that the DY-605 was used during 87-90 and the DY-606 was used from 90-93.
Does anyone know what the difference in the sensors are?
Here's a link to 50resto's site showing the different sensors specified for each year:
Mustang HEGO Sensors
Any input would be greatly appreciated.