I have a 2008 town and country with a 3.3l and 175k. The van is giving a p0403 code. I have replaced the egr, ait, throttle body,upstream 02, and cleaned out the upper injector harness that is missing(and still can’t find) seal. It will run rough for a little while, or die right after starting. The exaust runs clear or slightly visable. this last time it came on quickly. If i unplug the egr it will run ok. but it does smell. not sure if it is rich or exaust.
When I first started having an issue I was getting several codes. From egr, misses, throttle body, Injector errors. I replaced the egr first, then the throttle body. They didn’t fix it. I then took the intake manifold off to move the injectors to see if the codes moved. when I did that I unplugged the harness that runs to the injectors, ignition, egr, and water temp sensor. When I did I noticed water inside the connector. I cleaned it out and it ran fine. It started acting up again. It was again the plug. This time i noticed the connector had a seal missing. I filled the connector with dielectic grease and zip tied a bag over it till I could find a seal. Now it is running rough again. I took the connector apart and cleaned it out. but that is not the problem. The only code that comes up now is the p0403 for the egr circut. I got a code for the upstream 02 and ait. I have replaced both.
Thank you in advance.