Holy crap.. :Eyecrazy: That is almost certainly the problem.... Those butt connections change the resistance and continuity of some circuits and interrupt the signal to the computer. Plus theres no way to tell if their tight enough connections... The 2.7 harness will not work with the 3.5. You will need to get a used 3.5 harness, 02-04 years. Replace that complete harness, with a good used one, then see how she runs-- It will save lots of time and trouble..
All chrysler vehicles have the same code. So if you see the P code for something that is not possible on an intrepid on a generic code definition page that is why. All chrysler vehicles have the same code numbers. An Evap leak in a dodge ram will be the same number as an evap leak in a intrepid. Oh and there is absolutely nothing wrong with butt connectors as long as they are weather tight. A self soldering butt connector is the best way to go, they have solder on the inside and shrink tube on the outside, they make a good connection and seal out the environment. The normal butt connectors will work for a little while untill corrosion starts if not properly sealed.
my car was 2.7 2002 swithched to 2002 300 3.5 i have a 2002 3.5 trep ecm will that work, there was a topic about a 300 ecm that was a faster type i dont remember do i need that one or can i get the dealer to prog the 1 i got grom the 02 trep 3.5 cause my car runs like crap ???