I have been working on getting this Durango running right since I bought it in December, finally got my idle issues resolved after replacing, fuel pump, IAC, TPS, Air Filter, O2 sensor and running fuel cleaner. Now that it seems to be running fine its not... I have two of these with 5.9's so I have some equal comparison etc. The one without any issues gets regularly 15-19mpg in mixed driving and has great power across the board. The one with issues the computer says at best I am getting 10.1mpg even though on a long trip I hand calculated around 16. That is just a symptom but another and bigger one is that the truck has no power once it shifts into 3rd or OD. Let me try and explain. If I hit the throttle from a standstill the truck roars to life and has EXCELLENT power, climbs through the RPM's to about 4400 then shifts nice and firm into second starts to pull hard again then refuses to go above 2200 it will then shift to 3rd and same thing doesn't want to climb above 2200 now if I floor it and force a kickdown to 2nd it will run all the way up to 4k+ and pull like a freight train. I decided to try towing my small trailer this past weekend just to see if the trans was slipping or something else. Same exact thing pulled the trailer without any issues in first then second up to 2200 then 3rd to 2200 and that's it! Transmission is shifting nice and firm in all situations has a very good RPM drop between gears etc so I don't think anything is going on there mechanically. I know bad ECM's can cause some weird issues has anyone experiences anything like this?

Thanks for any input!

 

wow no ideas?

 

Can anyone at least think of anything to help push me in the right direction???

 

so to add to my interesting issues yesterday the truck decided it will only go into limp mode, this morning I reset the ecm, reseated the cables into the ECM and started up with no CEL and drove off fine but then went into limp mode again. I am really starting to wonder if my problem is the ECM at this point too many odd issues that don't seem to relate. I would really appreciate some input and thoughts.