Would a O2 Sensor with part number DY 604 (FOTZ-9F472-E) fit my 94 Ford Escort Sport 1.9 >> In the description says it will but if I look into motorcraft website it says its for a 91 or 92 Escort. Are this sensors universal or is there a difference between them.

It could be a 3 wire sensor and your newer one a 4 wire. It will fit the threaded hole, but the plug may not work. If you can rewire the sensor correctly it will work. The 4 wire has a ground for the heater and a ground for the sensor. While the 3 wire has a common ground for both.

The description reads:

"The plug on these have a 4 way connection with 3 male pins and 1 female pin hole"


That means it has three wires?

And if it is a three wires connector ... any hints in how to rewire it to a four wires...I am fairly confident with wires and electronic things as I am a PC tech...so it may be familiar to me but hints and tips are greatly appreciated.

The 3 wire have one gound, the 4 wire have two.

Just add the other ground wire to the single ground wire.