Are you going to answer my question about the D4 light?
No the Dr light is not blinking and stoveguy it could very well be that but I was trying to see if there were ways I could try and fix it from home because I read about and there were a lot of people asking the same question on different forums but no one answered them
If the D4 light is not blinking, then the transmission is doing everything it is expected to do. The next thing I would look for is a vacuum leak in the engine. If the manifold vacuum at the MAP sensor is low, the transmission will start to look for a lower gear because it thinks you are calling for more power.
Now that you put the Lucas in there, I think you will need to do a transmission fluid exchange. By Honda definition, that means three drain and refills with four complete cycles through the gears including torque converter lock up between each drain and fill. The new type Honda ATF should help with the shifting problem, especially cold shifting.
BTW, does the D4 light come on when that gear is selected? If all the others do when selected but that one does not, then it might indicate another issue. This is important.
I would still look at the TCU and check for burnt resistors and blown caps. See my earlier post. This is a common problem.