I got a 2006 Chrysler Pacifica Touring back in 2014. Ever since I got it, it's had an issue I've never been able to diagnose/fix. If the car idles too long, it will start to idle rough, revving up and down. If we let off the brake to start moving forward, the car will either lunge forward, or hesitate and not go at all. Most of the time, under normal driving conditions, it wasn't an issue. But every once in a while it would happen, if we sat in line at a drive-thru for too long or something. It always goes away after we get back to normal driving with minimal idling. Over the years it's gotten progressively worse though. I've tried a lot of things to fix it. Cleaned/replaced the throttle body, replaced spark plugs, replaced idle air control valve. About a year ago, it started throwing codes P0032 and P0038, both for O2 sensors. I replaced it with an aftermarket O2 sensor but still got the same codes, so I then tried one from the dealer but that didn't get rid of the codes either. So from then on, we've just been driving with the check engine light on. We also replaced the PCM about 3 years back, which I mention because the last mechanic I had look at it, suggested trying that after having ran out of ideas, but I didn't want to try that since at that time, it had only been about 2 years since we replaced it the first time (so it seemed unlikely to me that that was the cause), plus I really didn't have the money to go experimenting with it.

I had pretty much gave up, and was just hoping the car would make it a few more months until we could get a new one. But today, the problem got worse. Now, it sometimes hesitates when I'm accelerating, even when the idle problem hasn't been acting up. Other than that, it's driving pretty normally, just sometimes when I'm trying to accelerate after stopping at a light or something, it takes several seconds before me pushing the gas pedal starts to kick in. I ran the codes, it still has the P0032 and P0038 codes, but now it has 2 instances of the following code: P1697 - EMR (SRI) Mileage not stored. I'm not even sure if that code is relevant to the problems I'm having, nor do I know how long it's been there, since the check engine light is on all the time anyway. I went ahead and cleared the codes to see if it comes back along with the O2 sensor codes.

Sorry for the wall of text, just trying to give the whole back-story here. Any ideas what could be causing all of this? Is the new hesitation thing likely linked to the original problem, or is it something new like a failing fuel pump? Any help/advice would be greatly appreciated. Thank you.

 

IF you have the 3.5 l V6 motor, have you checked the EGR valve for sticking open and it's piping for carbon blockage?

 

This sounds almost electrical to me, have you checked the output of the alternator and the battery?

If electric interference or wrong voltage is coming out, this can knock sensors out and cause all kind of weird issues.

Also what fuel are you using? I'm not sure what you would call it state side, only know UK side and it's either E5, E10 or E15, the 5, 10 or 15 relating to the % of ethanol in the petrol.