96 Ranger 2.3 stick bucking

It bucks Only if I let off the throttle slightly or totally and then if I resume speed it will buck, runs fine if I don't decelerate first and then accelerate back to normal speed, many new parts
no better....HELP!

1996 Ford Ranger, 4 cylinder 2.3 Liter, 5 speed,
vin .... 1FTCR10A6TUD58993,

Thermostat and Anti - freeze NEW
Coolant temp sensor NEW
Throttle position sensor NEW
Idle air control valve NEW
EGR valve NEW
Injectors , NEW, not rebuilt!
Fuel pressure regulator NEW
Mass air flow sensor (Refurbished), identicle problem as old one
Spark Plugs NEW double plat, Autolite APP 104
Wires, Autolite Professional, NEW,
EGR vacuum selenoid NEW
EGR valve pressure regulator NEW
EGR valve NEW
Air filter NEW
Air Filter housing, USED like new
PVC valve NEW
Fuel Filter NEW
Oil and oil filter change Castrol 5-30, Purolator filter
Changed to buying Shell gasoline exclusively and adding
Chevron Techron fuel system cleaner

Fuel pump has been checked and pressure is correct
The fuel pump pressure and the air box replacement, fuel additive
was suggested by a Ford mechanic ASE certified .... he cant figure it out

Auto Zone or Advanced will pull the codes free. Post what codes you are getting.

I forgot to mention that my CEL IS NOT on and it is working....I went to Auto zone and they said that my EGR valve was fauty, I bought a new one and also the pressure thing and the relay, installed all and still bucked, went back to auto zone and did another scan, no problems found!

A few people on the forum have purchased after market EGR valves. I've found they are made for more than one engine. They used to come with a pack of spacers { Look like washers} you have to look at the information sheet and install the correct size or they won't run properly. When I had a garage I saved them with the sheet as a few cars came in with this problem.
Another man on the list went back to Advance and they had a number wrong in the catalog. This was for an Aerostar van. Ford advises to clean all piping and EGR openings but this normally sets a code. Another man threw his pack away and didn't look at them.
I've found many after market plug wires with poor crimps at the plug end. I have a set of crimpers for both size plug wires. Most of them weren't happy to pay an hours shop time to check out their vehicle for new plug wires they installed. Remember the center wire is double backed under the connector.

Here's 2 ideas. First, get a can of carb cleaner or ether and spray around all you vacuum sources for leaks, including intake gaskets. If you have a vacuum leak, rpms will rise. Second, check your motor mounts including the transmission mount. Don't just look at them, pry them with a pry bar. At rest they rarely look bad. Good luck.