I need to replace the O2 sensor, poor gas mileage, soft sooty tailpipe
deposits, plus not being changed at the 60,000 mile interval. I was
told that the sensor in the '90 5.0 Mustang was exactly the same.
(except for the 3 wire connector that must be changed) Ford dealer
(parts) knew nothing of this, and in fact asked which one? seems there
are 2 sensors for this model. one costs 75.oo the other 86.oo MB
dealer cost for O2 sensor 186.oo
Does any one know which is which? numbers,size,?