Your map sensor is located right under the intake hat. So, if your standing in front of the car it's right underneath the intake hat. If, you goto napa, you will spend an arm and a leg. Pepboys and autozone are the cheapest.

Unscrew the intake hat and move it out of the way a little, Then there are 2 torx screws that holds the sensor in place. Unscrew, use a small flat head to remove the vacuum line. Once done, put everything back together. Yes, reset the ecm, take the negative terminal off the battery during the time you replace the sensor.

Kensai, your mileage sounds like me. I had the exact same issue.

 

holy crap, just came back from Napa and they wanted $120 or $161 bucks, dunno if it is different makers or not. I just called my local autozone and they wanted $66. So I am headed off to get one now.
I never bought much stuff as far as electrical from autozone, got burned a few times and just settled that autozone carries cheapo electrical stuff. But $66 and $120 is way off so I'll try the cheap one again and hopefully this will hold up to get my $66 worth!

 

I'm using the autozone part and it works great. lol

 

Okay, I finally bought the map sensor by duralast from autozone for $66 plus tax. I installed it, and reset the pcm and filled up with a full tank of gas. Will drive it for a few days this week to see if mpg numbers go back to norm if not hopefully higher!

Otherwise, I will have to fork out another $120 bucks to Autozone for a front and rear 02 sensors. I hope these 02 sensors are basically easy to replacement without alot of stuff to remove to gain access to the sensors.

On my way back from the gas station, I did notice the D responds very very well, much more sensitive throttle response since map sensor replacement and pcm reset. Then again it may just be a placebo effect of mentally knowing you change something and expecting immediate results! haha

I took pictures of the install so I will post it here and make a DIY link also.

 

Today is my first day to take my D to work, during the 10 mile trip from home to office, I DEFINITELY feel a very improved power response from my D. I am not sure if it is due to the new replacement map sensor or the pcm reset or little of both. But damn, it is hard as heck to keep a light foot without the Truck launching or accelerating like a rocket! haha I won't be able to get a good stable mpg figure until I run this full tank down to get a final mpg estimate with the new map sensor. If anything I am already really happy at least with the new power response time!

 

Noooo, this thread is about improving gas mileage. lol

 

As far as the O2 sensor, you really only need to replace the one before the cat, this one tells the ecm if your car is running lean or rich. The one after the cat only monitors the cat's efficiency.

 

When I did the TPS it took 300+ miles to fully reset. I was going to pull it but held on even during the 8 mpg's and it popped out of it one day?????......IDK

My right foot is naturally heavier than my left as well........LOL

 

There are a couple of guys in the 2nd gen dakota forum that's going to try the map sensor. Watch for their results.

 

Kensai,

Any update on your mileage?