Since you replaced the VSS, I guess you are a DYIer, so here is the information you need to troubleshoot this yourself.
Under the dashboard on the passenger side right next to the kick panel, you will find a plug with two wires going to it. It should have a cap on it but it might be missing. This plug is not plugged into anything. The wire colors are red and green/blue. Short the two pins of this plug with a short piece of wire or paper clip.
Turn the key to the on position and the D4 will blink a code.
One short blink = lock up clutch does not engage/disengage or unstable idle speed. Lockup control solenoid valve A
Two short blinks = lockup clutch does not engage. Lock up control solenoid valve B
Five short blinks = fails to shift other than 2nd and 4th gears, lock up clutch does not engage. Short in A/T gear position switch or wire.
Seven short blinks = fails to shift 1-4, 2-4 or 2-3 or stuck in 4th gear. Shift control solenoid valve A or wiring.
Eight short blinks = fails to shift, stuck in 1st or 4th. Shift control solenoid valve B or wiring.
Nine short blinks = Lockup clutch does not engage. Countershaft speed sensor or wiring.
One long blink and five short blinks = Transmission jerks hard when shifting. Mainshaft speed sensor or wiring.
Four long blinks = Lockup clutch does not engage/disengage or idle speed unstable. Faulty lockup control system.
Four long and one short blink = Fails to shift 1-4, 2-4 or 2-3 or stuck in 1st or 4th. Faulty shift control system.