I’ve been the proud owner of a 2019 F-250 with the 6.7L PowerStroke since the fall of 2021. I bought the truck with roughly 50,000 miles on it, and since then, it’s been my daily driver. I love everything about the truck. It’s got plenty of power, looks good and has a comfortable cab to top it all off. From a fuel efficiency perspective, I was able to get 17-18.5 miles per gallon out of the truck when I first got it. However, I started to notice that the fuel efficiency was slowly starting to get worse and had dropped to around 16.5 miles per gallon by the end of 2025. I didn’t think too much of the loss in fuel efficiency because I had gotten a new job, and started driving the truck 70mph on my new commute to work, rather than the 55-65mph on my prior commute. Plus my new commute has a long, steep grade so I figured that was to blame.

Fast forward to about mid May of this year. The truck has 158,000 miles in it, and I had watched my fuel efficiency slowly fall to around 15.7 miles per gallon. At that point, I started to question what the cause could be. I quickly ruled out the air filter, as I don’t drive in dusty environments and I keep my filter changed pretty regularly. I was also able to rule out fuel filters, because I had recently changed all three of them (both OEM and the truck has the S&S disaster prevention kit). I also run Amsoil injector cleaner on a regular basis. 

At that point, I was stumped. I had gone through everything I thought the problem could be in my head, and then one day by chance I came upon a video saying that a dirty MAP (Manifold Absolute Pressure) sensor could be to blame, due to the carbon in the exhaust gases from the EGR valve (Exhaust Gas Recirculation valve) passing by the sensor’s opening. I found out that a dirty or stopped-up MAP sensor could be to blame for sluggish acceleration, bad fuel economy and inconsistent turbo gauge readings. All symptoms that I had been having. And the video mentioned that the MAP sensor can be clogged or cause false readings with as little as 50,000 miles on the truck. 

So I decided to stop by my local Ford dealer and pick up a new MAP sensor for $127. I figured mine was probably due for replacement going by the information I learned on the video. Once I got home, I grabbed a 1/4” drive ratchet and a 7mm socket and went to work getting the old MAP sensor loose from the top of the intake manifold. When I got it out, I was absolutely shocked to find that the MAP sensor was totally clogged with carbon. I have no idea how the truck was doing as well as it was. Let alone how it wasn’t prompting a check engine light. So I swapped the new MAP sensor in and closed the hood down. The whole process took about 5 minutes. 

Fast forward to today, and I am pleased to say that my truck is back to its old self again, and getting 18+ miles per gallon again. 

All that being said, if your truck isn’t running quite like it used to, it’s probably worth it to check out that MAP sensor, and replace it yourself in five minutes, rather than pay the dealer way more than you need to for a simple replacement. 

Is your 6.7L not running efficiently? This sensor could be to blame.