I had this same problem, loss of power after you take off, as soon as I shift to a neutral bring up the rpms high I could drive ok. after a drive when you put it in a park and wait a minute the car starts to rattle. I tested it and found that the o2 sensors were bad. I replaced both upstream and downstream sensors by a bosh type brand. They worked good until same problem started again. Tested it again found one sensor bad and circuit high voltage. I checked online who is the OEM for chryslers oxigen sensors and found it is Denso. So I ordered those through Autozone, replaced them and my car runners like new again.

 

I am having the same problem with my 100K 05 but seems like only when the Pac is cold or running for 5-10 minutes. From reading this post I am leaning to either EGR or O2 sensors but I hate throwing parts at the car hoping to fix it.

 

I was having the problems, on a 2007 4.0 fwd, with approx 44k it would surge around 900 to 1200 rpm while driving, and just above idle in park. I was told by 1 dealer that it was carbon build up in throttle body. so I cleaned the throttle body and still same problem. I took it to dealer and thier dig was the EGR valve. which was replace under warranty. they also updated the engine managment computer. right now it seems to have cured the problem, but will drive for a few more days and repost results. but for now it sounds like you problem is a EGR valve. "IMO" hope this helps.

 

might want to chech cats? i know when cats start giving problems it makes u think u have a fuel system problem/what kind of codes do u have? hope this helps

 

Replaced the plugs last weekend and that didnt solve the problem but it does run better. I checked for codes and there are none. Next up is replacing the EGR since it didnt cost much.

 

Solution to the loss of throttle
The Chrysler computers need a signal from the front O2 sensor to run correctly. What is happening is the O2 sensor is not putting out a signal until it is warmed. This happens after a few minutes of driving but until a correct signal is sent out by the O2 sensor, the PCM (engine computer) is on its own deciding how much fuel to inject into the engine based on your throttle position and water temperature. It has a special program to do that; it is called open loop. What is happening is the computer is going into closed loop and expecting a signal from the O2 sensor. Because of emission standards PCM’s go into closed loop as quickly as possible. To get the O2 sensor sending out a signal quickly, so it is working by the time the PCM goes into closed loop, engineers have added a heating circuit to the O2 sensor. The sensor must be above 600 degrees to output a signal and this is where the intermittent problem starts to happen. You can let the car idle in the driveway for half an hour and 90 seconds into your drive you lose your throttle. If it is the O2 heater circuit causing the problem, slide the shifter into neutral and push the throttle down. Eventually the engine RPM’s will raise (maybe 5 seconds; seems like forever) and then hold them at 2000rpm for 20 seconds. This will heat the sensor and the throttle will work correctly. If you stop at the store, or wait too long in traffic, you will need to do it again. If you notice a little hesitation the O2 sensor is too cold to work again.
There are 2 reasons for this problem.
One is your O2 heating element in the sensor is bad. To check it unplug the sensor and do an ohm reading across the 2 black wires. It should read 5 ohms. If not replace it.
Second problem; your PCM is not sending out 5 volts to the heater to heat it up. This could be a bad PCM or bad wiring. Checking the wiring harness from the PCM to the O2 sensor one will be ground and one should have 5 volts. The problem with checking it with the O2 sensor unplugged is that there is no load on the PCM and it could still read 5 volts without a load and zero with a load. Plug the sensor back in and check the voltage at the PCM. The factory manual says the heater voltage is supplied to the O2 sensor bank 1 sensor 1 through pin 18 (Black/Orange plug) C2 PCM. It is the second plug up from the bottom and has an orange strip on it. The wire is a brown wire with a tan strip. You have to pull the hood, that covers the back of the plug, off and insert a thin wire into the back of the PCM plug reaching in as far as you can. This is not as easy as it sounds so I recommend unplugging the plug and check using an ohm meter to make sure your wire has contacted the pin. Before you reinsert the plug back into the PCM check the continuity of the brown wire with tan strip to the O2 sensor plug. If the wire is good plug the plug back into the PCM. Start the car and check for 5 volts. If there is no voltage on this pin the manual say replace the PCM unit.
I wanted to make sure the PCM was causing the problem before I spent a lot of money on a new one. All you need to do is supply 5 volts to the heater so I bought a 25 watt DC/DC 12V/24V step down to 5V on Ebay for about $15 including shipping. (I think you could get by with just a 5 watt) I cut just the positive black heater wire about 8” from the sensor and connected the 5 volt wire from the step down power supply. The other 3 wires are still in place. Use an ohm meter to find which black wire is the ground and the other black wire will be the power. O2 sensors have 4 wires 1 blue, 1 white (O2 sensor voltage) and 2 black wires (power for the heater). We have not had any more problems with the throttle so why spend the money on a new PCM. Fixing it this way will keep an “Check Engine” light on all the time. I’ve thought about adding a resister to the dangling heater wire under the car but my wife has become so use to warning light on the dash (it took me a year to figure this all out) that I didn’t go to the trouble.
Before adding a different power supply make sure you remove and clean your ground wires. They are located under the battery box up front. There are 3 of them. I added an extra ground wire from the negative post to the body grounds. These cars use 5 volt for sensors and any grounding problems will cause sensor problems. A sensor problem causes the body/engine computers to do strange things.
For those who claim this is an EGR problem I have to disagree. If you have rough idle, misses on acceleration, and hesitation then EGR is your problem. Those of us who have problems with a loss of throttle, sometimes, will know exactly what I’m talking about. It is like your car is ignoring you! This is an O2 sensor problem.
What we don’t realize is that today’s cars are accelerated by computers and not us. We request to the computer to go faster by pushing on the gas pedal. The gas pedal opens up the air to the engine and by way of a Throttle Position Sensor tells the computer how fast you want to go. The computer then pulses the injectors to reach the RPM’s needed. The PCM then checks with the O2 sensor to see if there is too much or too little gasoline going into the engine. It then adjusts the fuel injector pulses to get maximum air/fuel ratio. When the O2 sensor is not outputting the correct voltage, when the PCM is in close loop, it understands the voltage to say “Too Rich; Cut back Fuel” and the short term fuel trim bank will pull back. My “Short Term Fuel Trim Bank” was at a -30% when I would lose my throttle.
I hope this helps,
steve

 

Having these issues only after replacing my original O2 sensors (@ 120k miles) with Bosch O2 sensors.... Had P0440 and another error for EVAP vacuum... I think we found the hose that was causing the issue (the one connected to air filter was chewy, so cut and clamped... But now these new issues of when idling either sputtering or too much gas.... Ordered NTK o2 sensors. Should be here tomorrow. Funny that I didnt have the issue until replacing with Bosch. But I also get crappy mpg... 15. So replacing those, and I will get an EGR valve to replace next month. Also just ordered a PCV valve. I can't remember when the last time I replaced that if ever, so hoping that this all will solve the problem, and give me a lot better gas mileage.

As to the fix that keeps the check engine light on, we are in VA and can't pass emissions with that on, which is a stupid yearly thing, so that's why I'm fighting all this, since the check engine light has been on since I bought the car... well soon after.

 

I am just hitting about 90,000 on my 05 Pacifica Touring, I've owned it less than a year and we love the car. I am experiencing intermittent surging at idle and at cruise, also have stalled a few times at low idling speeds. This is happening more now than not. The info in this thread is great. So, I will replace the EGR and the O2 sensors along with plugs and a few other tune up parts. I will replace one part at a time starting with the EGR and then both the O2 sensors. I will post which one fixed it for me. I am taking the car on a long trip with the family across a few states in a couple of months and hope this fixes my problem. Thanks again for the info!

 

Clean your throttle body and change the EGR first. I highly doubt your o2 sensor has gone bad. I had the same symptoms and done the very same thing with excellent results. Drives perfect all over again.

 

Thanks ttype, will do. Yes, I forgot to mention I did clean the throttle body already. It helped with a sticky throttle peddle. I will be adding a K&N filter also. Trying to squeeze as much fuel economy as I can out of her. I currently get about 18 MPG combined right now. I am seriously thinking of installing a Hydrogen cell also, still researching that one though.