Plymouth Repair: possible transmision problems, obd2 scanner, shifting gears

Question
Hello,I've got a 99 Voyager van with a 3.1
My mechanic changed the cam seals as they were leaking oil.
My problems seemed to start after this but not sure if its related.
At a cold start, the engine runs very erratic with rpm rising and falling.
When i start driving it hesitates,feels like the trany is shifting gears to a lower gear then back to drive with high fuel consumption.
I've checked the trany fluid when hot and all is well,full and good color.

If i change gears manually from drive to second,i can't feel a change.
If i speed up to 80 kmh in drive, still no change in gears until the vehicle is warmed up.When warmed up ,things seem to run a bit better.
I've done a tune up with new spark plugs,wires,cap and rotor but was unable to remove the #1 plug,it was just to tight in the block and didn't want to break it in there,so i left it.
The other five plugs looked good,no carbon deposit,just white at the tips.
I've replaced the O2 sensor (pre cat).
I've checked the TPS by removing it and driving which makes it run like, well you know what,so thats not it.(check engine light comes on of course when i do this but i clear it after)
There was a code stored at one time (P0123) but i cleared it using a cheap obd2 scanner.This was pre testing,before all this started.
I've also noticed that at a cold start,if i play with the center wire on the TPS at the connector ,i can control the rise and drop in RPM.Again this is until the engine is warm ,then when i try the wires it's not so noticeable.
Could all this be from a clogged trany filter as thats my next goal.
Thanks for any input.

Answer
You seem to have a few problems here but on reading your question the all appear to center on the TPS. So that where I'll focus the diagnostics. The most obvious problem is the TPS signal wire. Both the transmission and engine controllers need a good signal from the TPS for proper operation of the transmission and engine. Since you stated that the engine RPM would change when you wiggled the center wire on the TPS leads me to believe that you have a concern with a partially broken wire or a loose wire terminal at that location. Other than replacing the wiring terminal the only thing you can do is to give the pin a little twist with a pair of needle nose pliers to tighten the connection a bit. If that fixes the problems then plan on replacing the wiring and the connector sometime in the future. If it doesn't, then you'll need to use DVOM to check the TPS signal at the transmission control module. To check that, remove the wiring cover from the transmission controller wiring connector without removing the connector itself. Back probe cavity 12 with the DVOM, set to read DC volts, and with the ignition on but not running, slowly open and close the throttle. You should get a reading of about 1 volt at closed throttle and about 4.5 volts with it held wide open. If you don't get any voltage readings then you have a broken wire somewhere in the engines wiring harness.