Engine Control COmputer Programming

Hi. I own a Ford Explorer 1996, 4x4. I purchased a Engine Control Computer, I researched a little bit, and it turnes out that the new computer did not have the same serial number as the one it came when it was newly purchased but rather a compatible one(newer model I guess). The old computer was damaged. The problem is that the vehicle has a constant problem now, it trebles and the revs go up and down on iddle. Even, when I drive long distances, the revs goo all the way down to zero and the engine dies. That is very dangerous so my Explorer is now parked and I can't use it. A mechanic told me that i needed to "reprogram" or "reset" the computer and that he would do it for a fee. That sounded fishy... I changed almost all the sensors, and it does the same. Even a the computer diagnostic says that it works ok(even when the vehicle is trembling!!).
Please, any insight is well appreciated. tanks in advance

really, what you need is someone that knows what they are doing to look at it.

Off the cuff, a common problem for fords is dirty IAC's and it can cause the idle to hunt or the engine to stall. But the "trembling" you describe, might be a misfire. Hard to say from here.

really, what you need is someone that knows what they are doing to look at it.

Off the cuff, a common problem for fords is dirty IAC's and it can cause the idle to hunt or the engine to stall. But the "trembling" you describe, might be a misfire. Hard to say from here.
Thanks, Actually I have replaced the IAC valve twice. I also changed the 4 oxygen sensors, the EGR valve(the one that looks like a UFO).
Also, when the engine is trembling I unplug the EGR hoose, and the revs go up and it stops trembling, then I plug it again and it strts trembling again and all of a sudden, it stops trembling again, then I unplug the hoose again and the hoose vacuums(sucks)only but a little bit of air. And then it starts failing again(revs go up and down).
EDIT: I have noted, also that I unplug the TPC Sensor, and nothing happens. I unplugged the TPC on my mustang and the engine feels it unlike the explorer, the unplugging of the TPC has no repercussion on the engine.
I'm starting to think that I need a priest instead of a mechanic hahaha

Thanks, Actually I have replaced the IAC valve twice. I also changed the 4 oxygen sensors, the EGR valve(the one that looks like a UFO).
Also, when the engine is trembling I unplug the EGR hoose, and the revs go up and it stops trembling, then I plug it again and it strts trembling again and all of a sudden, it stops trembling again, then I unplug the hoose again and the hoose vacuums(sucks)only but a little bit of air. And then it starts failing again(revs go up and down).
EDIT: I have noted, also that I unplug the TPC Sensor, and nothing happens. I unplugged the TPC on my mustang and the engine feels it unlike the explorer, the unplugging of the TPC has no repercussion on the engine.
I'm starting to think that I need a priest instead of a mechanic hahaha

if connecting the EGR makes a difference, then that is a clear indication that its not working properly