I had this same type of problem on my 2000 caravan about 8 years ago. A friend of mine was a transmission mechanic for chrysler for years and had me unplug the sensor on the trans. That he said was for smog related signal and it has ran fine ever since. I want to say if I remember right it was located on the front side of the trans. Near the back of the block. IT'S been a while though. If I get a chance to crawl under in the next few days I will send you an update.
October, 1, 2012 AT 10:14 AM
Ignore the previous advice as it is nonsense.
Of those 3 codes, only the first one has anything to do with the operation of the vehicle. The second 2 are EVAP emission codes. The P1698 indicates that the PCM is losing communication with the TCM which probably means the TCM is going bad but could be a wiring issue also.
October, 1, 2012 AT 5:14 PM
The p0455 could be a stuck open canister purge solenoid.I agree with wrenchtech ronsons reply doesnt make sense.