If anyone can help I would really appreciate it. Local shops want up to 5 hrs at $88/hr to diagnose this issue!Ouch. So far I have found that it is usually only a few things that cause this problem, shorted or open wiring, bad injector, and bad PCM. And a few forums have said the TPS.
'02 Town and country 3.8 Liter. Studders at 1500 RPM, and slow takeoffs.
Code on instrument cluster and Can Scan 3100 is P0205 for the # 5 Cylinder injector circuit malfunction. You can put your foot on the brake slowly idle to 1500-1600 rpm and it will start to run rough studdering, misfiring for as long as you hold it there. Once you get to 2000 rpm goes away. Going up hills is the worst as well as normal takoffs. Here is what I have done so far....

1-Tested the TPS sensor ( since it was RPM related) TPS sensor moves smoothly with no opens or jumping throughout the range. .80 ohms-4.94 ohms.
2-Checked ohms on all Injectors all measured 12.0-12.4 ohms.
3-Removed Cylinder #5 injector bench tested and activated fine.
4-Swapped #5 injector for #1 (to see if the code followed).
5-Checked injector wiring back to the PCM nothing exposed or broken or loose.
6-Disconnected the #5 injector wiring harness. Tested for continuity between the ground pin (injector end )back to the ground wire pin #10 in the Grey and Black top PCM connector(disconnected from the PCM) as well as to chassis ground. Checked good.
7-Checked continuity from the power pin in the (injector harness end)back to the #15 wire in the PCM connector (BLK and Orange wire) tested good. Checked for continuity to ground and there was none (assume no short to ground?) Also this confirms no opens in the wiring.
8- When I disconnected the pcm there was condensation all over the pins and the plug so I removed the PCM, blew it out with a compressed can of air and let it sit in the house for 2 days to dry out good. (not good!)
9- Pulled spark plugs and replaced. #5 was very wet.
Put all back together and ran great for 3 weeks. Could not force the problem no check engine light all was good!

Then it rained the other day and we are back to square 1. So I did the following....

1- Unpluged top (Grey and Black) PCM connector, sure enough Pins wet and droplets of water on connector( really not good!)
2- Dryed out PCM same as before 2 days.
3-Pulled #5 spark Plug dry ashy burning good looks like.
4-Put PCM back in ran the vehicle and same thing 1500-1600 rpm starts to run bad then sets the P0205 code.
5-Used a long screwdriver to listen to the injectors that are accessible all are clicking away including #5.
6- pulled it in the garage in the dark and looked under hood for any spark plug wires arching, nothing. Checked #5 wire getting plenty of spark!
7- Checked for continuity between my positive battery post and the #15 pin inside the PCM and there was on all the injector driver pins continuity. Checked for continuity from the negative battery post to the #10 pin in the PCM (ground) and it was there.
8- Here's where I am thinking the issue is......checked continuity from the positve battery post to the Same #10 (Ground) pin and there is continuity there....This in my mind is not right. But I could be wrong of course, I am not a mechanic just broke and cant afford one!!!!

Now I did notice the dome lights flickering while running it in the garage in the dark so I put the trusty screwdriver on the alternator and it sounds horrible. Could the alternator be sending wrong amps and signals to the PCM? Or is it simply the water in the PCM? Why did it work the 1st time I dried it out and now it doesnt work when dried out? Suppose I just got lucky the first time and now the PCM is shot! The code is for an open circuit in the #5 injector which is working fine as far as I can tell so thowing a false code? Any ideas would be great!