Ford Repair: Ford Ranger, crank shaft position sensor, shaft position

Question
QUESTION: The questions pertains to a 97 Ford Ranger 3.0L, manual trans. W/ A/c.  I detect a engine miss during acceleration( more detectable with the A/c on) 20 -35 MPH. When I am de-accelerating with the a/c on it feels like trailering ( while pulling a trailer and you let off the gas and the trailer hits the vehicle from behind). I have replaced the crank shaft position sensor, TPS sensor, not too long ago replaced fuel filter, wires, spark plugs, cleaned the MAF sensor.  Coil pack checks out in the driveway. Can someone or someplace perform a bench test (when the coil pack is hot from use)?. Can you suggest how I can determine what is causing my engine miss ?
Thanks,

ANSWER: You most likely need a new DPFE sensor.  It's a little rectangular box attached to the intake manifold with one wire plug and 2 hoses attached to it.  This sensor is used to help control the EGR system and they fail a LOT.  They generally cost around $70 and are available from Ford and some other parts stores. Hope this helps,
Jason

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QUESTION: Would like to confirm that you answer in the same way if I do not have a 'Check Enging Light' at this time.

Answer
With or without a check-engine light, I would respond in the same way.  The reason being, most fords use a DPFE sensor, some vehicles are designed in a way that causes the DPFE to fail more often.  The 3.0 engine is probably the worst one for this problem, whether it be in a ranger or taurus.  The other giveaway is the "trailer-hitching" you described.  That is a classic telltale caused by the EGR being opened too far.  (the DPFE tells the computer how far the EGR is opened, if it is failing it will give an incorrect reading to the computer, which will open the EGR valve farther until it gets an acceptable reading).  Since it has not completely stopped sending a signal, the computer does not detect the problem and will not set a light.  Best regards,
Jason