I have been trying to figure out why my 2000 dodge durango 4x4 with a 5.9L had a loss of power and really bad gas mileage since 40,000 miles. Below are the things I did but never fixed the problem.

Intake, Exhaust, new plugs, new rotor and cap, new msd ignition wire, throttle position sensor, O2 sensor, etc.

After years of trying to figure out and trying everything in the book on how to improve fuel economy. I just about gave up.

Well, I had an issue with another dodge car where the map sensor went out completely. So, I gave it a shot on the durango as well. So, what does the map sensor do? It tells the computer how much pressure is in the manifold. Thus, telling how much fuel to pump in. Take a look at your throttle body, it will build carbon over time. The map sensor has a diaphram inside of the sensor, so over time carbon build up and the diaphram hardening up will not cause the sensor to fail but rather read inaccuratly.

After I replaced the map sensor:
Power return to like a new car condition
My gas mileage returned
Runs like a new car again
Engine no longer knocks

Those of you with poor gas mileage issues that have replaced everything else, may want to give this a try to get their gas mileage back.

I remember When I first started trying to figure this out, people with the 5.2L also had this problem.

To give you an idea about gas mileage, I was getting 13-15 mpg on the highway with the old map sensor at around 70mph. Now with the new one at cruising I get 18-22 mpg on the instant mpg monitor.

Huge jump in mpg. With gas prices the way they are, your map sensor will pay for itself in no time.

 

The map sensor would apply to any dodge truck with a 5.9L or 5.2L magnum.

 

Interesting. Can the original MAP be cleaned of carbon without screwing it up? After reading this I thought I might give that a try first. Yeah, I'm cheap!

 

No it can't be cleaned. There is a really thin silicone diaprham. When a map sensor goes bad it's because that peice of silicon has cracked or is starting to get hard. So thers nothing to clean.

 

Both of the 2nd gen. dakota's & 1st gen Durango's have tried this with great results. Take a look in their section with the same thread heading.

 

while i do agree with you on this, i believe that most of our gas mileage/poor performance problems point to the plenum gasket leaking do to crappy engineering. "hmm, i think we should put a steel plate on an aluminum intake, yep, that'll work just perfectly!" lol

 

For those non believers, below is a link to someone that has tried a new map sensor on the 2nd generation dakotas.

https://dodgeforum.com/forum/2nd-gen...-solved-5.html

 

Is there any way to test the map sensor before blowing $130?

 

Do I use Google maps to find the Map Sensor? Where the hell is it??? ..And does it cost $130?????

 

$66 at autozone. That's like the cheapest that I have found. The one that everyone in the Dakota's and Durango forums are using is the Duralast from Autozone. The 5.2L & 5.9L use the same map sensor no matter if it's in a full size, mid size truck or a SUV.

Trust me, you won't regret it. It will be the best $66 you ever spent. It will run like a new truck again.

The map & (1st O2 before the cat) work in conjuntion to give you perfect A/F ratio. If the map is old, the ecm will feed to much or to little fuel to your engine. It will also cause your timing to be off. This will cause your truck to run sluggish. No matter, if you put new plugs, ignition, etc. It will never feel strong.

Once you replace the map, it will feel like a new truck again.

The Map sensor is right underneath the air hat. It is attached to your throttle body.
Below is a picture of where it is located on a magnum 5.9L, I'm sure a 5.2L is in the same location.

https://dodgeforum.com/forum/1st-gen...-location.html

Your map voltage is suppose to be above 1.4v at idle, i think. However, it really needs to be at around 1.9v-2.0v for best result (new). The guys in the 2nd gen dakota forum did the checks. I personally just replaced it because, my map sensor is like 9yrs old. lol

Keep in mind, that as your map sensor ages, it will not read correctly, even if the voltage is in spec at idle. Due, to the diaphram hardening inside the sensor itself.