98 Ford Taurus Miss between 1500 - 2100 RPMS

Hey guys I have a taurus that is missing from 1500 - right above 2000 rpms. If you mash it to the floor it will not miss until it hits Over drive and drops down aroudn these rpms. If i accelerate slowly after the first shift it will do this in any gear in that rpm range. When stopped and in park I can get it to miss between these rpms but not as much as when driving. I feel a miss thats almost like a brake rotor shake in the steering wheel. This doesnt happen when on the brakes just when im driving between 1500 - 2000 rpms. This taurus is a 98 with a 3.0L OHV motor. The motor we replaced with a used one that ran awesome a few days ago. I did get a EGR code yesterday and repalced it and retested it with my snap on scanner. I also replaced plugs and the coil. The coil had a wear spot on the bottom and I was pretty sure that was the issue. But we replaced it and it still does this. Any ideas where to go with this? Im not getting a check engine code now. Thank you - JT

Does your Snap-On scanner allow you to access the component parameters? If so, there are fields in there for detected misfires on each individual cylinder. There will be a count for each cylinder, even if the count is not high enough to trigger a check engine light or diagnostic trouble code.

Also, check for vacuum leaks, make sure the air intake tube is securely attached to the MAF sensor and throttle body, clean the MAF sensor elements with appropriate cleaner, check the plug wires, etc. Is there a reason you didn't replace the spark plug wires when you replaced the plugs? For your concern, I'd suspect the wires typically before suspecting the plugs, unless the plugs were obviously due to be replaced.

-Rod

Ive checked over all of these things. Unfortunatly im stumped. Im starting to lean toward possibility computer may have to be reflashed to match motor. I have a 245 apt at Ford. They are going to drive it and scan it with there computer for free. I will know after that an update. I will post up what they found out Thansk - JT