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.
More background.
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.
I watched the video tester. My egr is an updated one starting in 2008. It is on the driver side rear of the car. It only has the metal tube that runs to the intake manifold, and one electronic connection with 5 wires. There are no vacuum lines that run between the egr and the engine. I thank you for the input, but I do not believe this is the solution to my problem.
just a small update. I gave up last night and went to work today. When I got home today i planned to work on it. First thing i did was start it up just in case something happened. It started and ran fine. So i decided to go and wiggle all the wires. I did and nothing happened. I let it run for 15 minutes. I then turned it off. Now it is running rough and dying out like it was yesterday. I only had it off long enough to run the codes with the key trick.
The rough running sure seems like it is related to the injector connector problem. A shop with the proper diagnostic equipment could do a test to verify each of the injectors are doing what they should be doing. One way is they install a fuel pressure gauge & pressurize the fuel rail, then pulse each injector one by one and verify the pressure drop in the fuel rail is the same, injector to injector. It will measure the same if each injector squirts out the same volume of fuel when it is instructed to be pulsed.
i think i may have to check that out. with the car running better with the egr unplugged makes me think it has something to do with that. but fuel sounds like something to look at. i checked the wiring today. all five wires are either going to the pcm or ground.