Afficio 450 developer type 4 or type 5

Type 5, it has a darker density.

Remove PCU, remove development unit, remove cover (2 plastic C-clips) remove filter, remove development roller (2 shoulder bolts). Clean roller and empty all developer. Pour in new developer, re-assemble unit. Reinstall drum and Development unit. Place a small piece of paper between the PCU and toner entrance hole to prevent used toner from entering dev. unit during calibration. Perform SP2-801. Remove paper form dev. unit

Thraser, your still battling this machine? Of course your readings will be off if you only have developer coverage over half the mag roller? That's where I would start.
I also now wonder about your model #, because I don't think that the 450 has a VSDP reading, but the newer ones do. It refers to the "immediate post-pattern output" of the ID sensor -not surprised that these readings would be whacked!

Hello sir; Just follow the steps;
1, dump entire dv use vaccunm cleaner to cleanup don't leave any dv inside.
2, thorughly clean out magnet roller by rubbing alcohal.
3, pour in new dv evenly.
4.Do simulation 2801 & 2805, the procedure as follow;
press"clear mode", "107", press and hold "clear/stop" key for 3 seconds, then press 1 for copier sp then enter2801 press start, after that go to 2805. same procedure. Let me know the resolve.

Do you know how to calibrate the toner/developer sensor?

Preform SP 2-801 then 2-805.That will do it!

To remove the Dev. unit.
1. Open the right upper cover and front cover.
2. PCU. (☛ 3.11.1)
NOTE: Spread paper on a clean flat surface that is free of pins, paper clips,
staples, screws or any other metal objects.
3. Loosen [A] (! x1)
4. Rotate bracket [B] left.
5. Development unit [C]
NOTE: Pull slowly to avoid scratching or nicking the development roller.
6. Set the development unit on the spread paper.
7. If you are temporarily installing a used development unit for test purposes,
perform SP2-220 and 2-802-1 after installation (☛ Chapter 5, “Service Tables)

Replacing the Dev. material.
1. Development unit (☛ 3.12.1)
2. Remove the development roller (☛ 3.12.3)
3. Empty toner [A]
4. Turn drive gear [B] to ensure that no developer remains in the unit or on the
developer roller.
NOTE: Dispose of the used developer in accordance with local regulations.
Work carefully to avoid scratching or nicking the development roller.
5. Pour approximately 1/3 of the developer [C] evenly along the length of the
development unit.
6. Rotate the drive gear [D] to work the developer into the unit. Repeat [C] and [D]
until all toner is in the unit and level with the edges.
7. Reassemble the development unit
8. Cover the toner entrance hole [A] with a piece of paper.
9. Install the development unit in the machine.
10. Turn on the main power switch, make sure that the machine has warmed up,
then perform the TD sensor initial setting using SP 2-801.
NOTE: When performing this setting, cover the toner entrance hole with a
piece of paper. This prevents used toner falling from the PCU into the
development unit during the TD sensor initial setting and interfering
with the Vref setting (toner density reference voltage).
11. After performing the TD sensor initial setting, remove the sheet [A] from the development unit.

This is how you replace and reset (calibrate) the new Dev. material.

You may want to consider putting developer into the unit. What is the copy count on the machine?

Auto setting. If you are getting light copies, you might need the developer replaced as well.

When developer goes bad you use more toner for one thing, but the main sign is a gray background in your copy. The print should be black but appears to be gray. The ricoh 350/450 was always noted to leak toner and developer as it runs. Check your machine and see if you see any small piles of toner, which also has developer in it, in the machine. Ther are small seals made of felt that need to be replaced if you have this problem. These seals rub against the drum sides....Good luck.