Could a bad/faulty MAP sensor cause bad fuel mileage? --DirtySCREW

 

Well there is a MAP sensor as well as MAF sensor. I think you may be refering to the MAF ( Mass Air Flow) sensor in regards to fuel economy. MAF sensors can cause poor fuel economy and some drivability issues as well. Easy to clean as its located in the zip tube ( tube between the air cleaner and throttle body) Get some spray cleaner such as Gumout Mass Air Flow Cleaner and spray the element inside the tube real good. May help but I see you guys in NC are getting some cold weather right now and that can also affect fuel economy. Good luck.

 

Dyno---thanks.....but I am referring to the MAP sensor (manifold absolute pressure). I've already cleaned the MAF and it did make the mileage go up about 1-1.5 MPGs for the following tank; but my mpgs have dropped back down again. I was reading some about the MAP sensor and how it or a vaccum leak could cause the MAP sensor to give false readings have have a very rich fuel mixture. If that is the case, it could explain my "not normal" MPGs compared to a LOT of other F150s out there.--DirtySCREW

 

its the weather. when its cold they loose economy. Mine does it every year. Wait until things warm up for awhile it will improve.

 

Your truck does NOT have a MAP sensor.

Your lowered fuel economy is probably due to a combination of winter fuel blend and the cold weather. You can look at the long-term fuel trim PIDs to see if you have a corrected "lean" condition (which would increase fuel consumption) due to vacuum leaks or fuel delivery problems.