FACTS:

2002 Dakota 4.7 sport/4 door
Maintenance always on schedule...

This has been going on for about 10 months
-Truck started getting 10-11 MPG city, while getting about 17 MPG Highway.
-Used to get about 15-16 city and 17-19 Highway
-So now my truck that used to get 350-400 Miles out of the 24 gallon tank, gets 240-260 miles if lucky.
-Idle a little rough at stop lights
-Noticed power loss, definitely not as powerful once this happened, I can feel it eating gas when step on the pedal, instead of the smooth growl that once was with the 4.7
-No engine light on, no codes showing

What I have done and checked for so far:

-Mechanic checked out twice and cleaned throttle body twice. (noticed a very small amount of power for a couple days, but that’s it)
-He keeps saying, it is not showing codes, and no leaks, and to also put a bottle of techron and use techron gas. Well I’ve done this 5 times in the past 6 months. Techron, Lucas, Sea Foam…… blah blah blah…. Done multiple times. (no help)
-spark plugs, air filter, full tune up, tranny fluid, transaxle fluid, changed out 6 months ago (no help)
-noticed Evap line had a crack by canister… changed them all out yesterday (no help)

Interesting things:
-Map sensor changed 2 weeks ago with duralast map sensor. Power back instantly…CHECK, idle smooth at stop light…. CHECK. Gas mileage after a tank… same or even worse..10.2MPG TO boot, after the week power loss back, rough idle at stop light back. Took map sensor back, bought another map sensor (just for shts and giggles), does not even help one bit (this is weird)
-Truck seems to get horrible mileage in the city but ok mileage on the highway.
-Oh not sure if this means anything... When i have been changing out the 2 map sensors, there is a little bit of watery oil looking stuff on the black main tube part that goes into the engine. (on the map sensor)


So the main concern is:
-Power loss. I notice it and I want my dodge back that I bought. The one that will peel out when stepping on the pedal a little hard with ease, and pass cars on the highway without sounding like using 2 gallons of gas to do so. I want my rumble back….and my gas mileage back. The 240-260 miles from a 24 gallon tank is unacceptable. This is very frustrating and I will have to sell my truck if I can’t fix it, which I don’t want to do.

My next plan was to start replacing random parts:
-Throttle position sensor
-O2 sensors
-spark plugs again
-coil packs
-IAC valve
-gas cap

But this is gonna get expensive fast , and what’s to say that it will even be the problem??

Someone, anyone, please HELP!!!

 

I will move this to the 2nd generation Dakota sub-forum.

 

cool.. it was in the 4.7 one. No replies??

 

check the power steering pressure switch and see if it is leaking inside the connector if so then it probably followed the ground to your o2 sensor

 

Yes these are your best choices

-Throttle position sensor
-O2 sensors

The rest are more for your idle and smog control

 

I had all the same issues and here is what I did I have more power and it's a blast to drive now
Do a cold air intake, flow master exaust , throttle body spacer , and a piggy back econamey chip from PCN (PCN-256)