Interested to see the solution to this. My truck is a 06 Dakota 3.7L and I've been having this issue a bit. I had the shop check my tranny because it felt like it was slipping when trying to speed up or go up hills. Turns out it was a misfire, plugs were gone. Replaced plugs and fixed the misfire, but it's still sluggish up hills, and worse of all, the misfire is starting to come back especially when I first drive the truck for the day.

More on the sluggish part. Is yours acting up in any other way when your going uphill or is it just slowing down and not wanting to speed up? With mine I'll be doing 75 on hwy and go up a hill and it will just slow down. I hit the gas and half of the time I can't get the rpms to shoot up any. I lose a good 10 to 15 mph going up hills. Acceleration is fine for the most part on the flat. I haven't looked into it much, but I'm thinking it's the transmission.

 

Dual, I have a 2008 4.7l V8 with that exact same problem. I have been dealing with this problem for over 3 years and have not been able to find a fix for it yet. I'm am convinced it's a transmission problem and to me seems like it has something to do with the 3 to 2 downshifting, but don't really know. I did the same thing you did, replace all different types of part and ran all different test and still haven't found the problem. I even took it to Dodge and all they did was scrach their heads and say they couldn't figure out what it was and wait for it to break and then go back. So Please if you find out what wrong with your truck please post back as it may help me with my truck as well. Thanks

 

Sounds like we are having same problem. I am saving up money to get converter and converter clutch replaced also need the kick down strap replace or adjusted.

 

Acceleration is fine on flat ground for me as well....but going up hill I am lucky to keep it at 40-45 mph. I believe I have trouble shot the problem to converter and converter clutch and kickdown strap... Just have to save up the money to get them replaced.

 

Before you texted that you have a 4.7 V8 I thought it was only the 3.7 that had this problem... like not enough power from engine to transfer power... sorry to find out you are having problems also. I believe I have traced back to converter and converter clutch as well as kick down strap. Saving up the money to get these fixed and I will post as soon as its worked on. And I have had the same problem with Dodge dealerships... You would think they would be better at figuring out this problem then anyone else.

 

since you had a misfire, your catalitic converter or both (not sure where the misfire was as you didn't mention) could be clogged, when you are going up hill, i'm guessing that it downshifts and revs higher. with the increased airflow from the higher revs, the cats could be causing restriction causing more backpressure which could then be causing your loss of acceleration and power.

try running a can of seafoam through the TB (the aerosol one is easier then the liquid one but that's my preference). it will clean the valves, pistons, and also help clear the catalytic converters.

It worked wonders for me when i had my misfire, i was having random issues on that bank after the misfire.

 

Has there been any luck with a fix for the acceleration problem you have been having?

 

Update : I purchased a remanufactured transmisssion and no change to power problem. I can say with certainty that this is not a transmission problem. I had an exhaust pressure test done and it checked good. So now it is having the full gambit done to include leaks TCM PCM MAP CrankShift position, throttle position sensor, fuel pump and anything they can think of, to include collapsed hoses. I will re-update as soon as I find anything out. If anyone has found a solution to this problem please help.

 

I did not see the EGR valve mentioned in any of the troubleshooting thus far. The EGR has a significant impact on engine power. An EGR acting up usually throws a code .... but not always, especially no code if the issue is any problems within the PCM-EGR loop.

 

It seems that I have the same issues that a lot of you are having with loss of power going uphill and high rpms with sluggish downshifting. I am following this thread to see what comes of it.