I have a couple issues, I am looking to buy a good but cheaper OBDII Reader ($50-$100), and I unforunatly cannot find much information on scanners themselves or where to buy. I am looking for the most features, and quality for my buck...

I also am having trouble with my 02' Caravan, I am getting a hard downshift at roughly 30mph, sluggish driving, using more gas..... I first suspected a tranny problem instantly, checking all fluids and temps... and with no signs, thought a while... I am now sure it is a PCM problem, the battery was disconnected and I do not believe the pcm has relearned. The problem still exists. Doe's anyone have experience with this? I do not have any coding, just what seems the pcm or possibly tranny acting up.

I have heard good things about OBDII readers, and I hear they pay off in the end, will a reader help me understand significantly more about whats going on with the pcm/tranny?

 

It could be the shift solenoid which may not throw a code until it goes into limp mode, so a cheap OBD scanner won't give you much info/detail. I've disconnected the battery multiple times without the problems that you mentioned.

Instead of buying a cheap OBD scanner, you would be better served by going to a transmission shop and having them look at it.