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.