1999 SL-1 auto trans problems

[dgboult]

Hello,
I have a 1999 SL-1 with a automatic trans. The car has 90,000 miles on it and until about a few months back it ran fine. The first problem was the reverse slam about 6 months ago then about two months ago it started shifting extremely hard up and down shifts, so I replaced the valve body with one from Valve body express (Yes I also changed the fluid and filter at that time). No engine light ever came on. The car ran great for a month, and now the car will sometimes feel like it will not shift out of 3rd or 4th when coming to a stop, or sometimes it will shift down so hard that it feels like I just ran over something. I notice it does it more frequent of up or down hill grades. To top it all off the engine service light will come on and go off sometimes. I borrowed one of my friends scanners and read the codes on one of the times the engine light was on and I got:

PO 732 - Gear 2 Incorrect ratio
PO 733 - Gear 3 Incorrect ratio
PO 783 - 3-4 shift malfunction

To me it sounds like somthing electrical because it only does it sometimes and the engine light will go on and off. Also I have not tightend the input shaft nut yet. Could this be causing it?
My manuals says the line pressure accuator, but I thought a new one came with the new valve body.
Sorry for all the writing I'm just trying to help you guys narrow down my problem. Any help would be greatly appreciated.
Thanks