Well here we go, so i have owned my WRX wagon for a few months now and recently my gas mileage has just turned to crap, when doing my oil change the other day i hooked my car up to my scantool and wanted to look at fuel trim data. Well Long Term and short term fuel trim was very normal so i looked at some of the other data. The pressure sensor showed only 11inhg, I was freaking out. So i broke out the old vacuum gauage it incidate i had 21inhg so no mechianical issues so i suspect a bad pressure sensor. I was wondering if anyone had run into this problem before i know that the small peizo crystals bend over time but i did not know if it was a problem.

thanks matt

 

The pressure sensor is a MAP which means manifold absolute pressure. Your gauge shows pressure relative to atmosphere so they will not agree.

 

crappy mileage, wat you expect from a turbo car
best ive gotten is 260 full tank

 

Mine is crap also, but I tend to drove with a lead foot.

 

I have to disagree that Map sensor is real time info on the intake manifold and can alert the computer of boost coming on.........

 

Yes, you are correct that it's real time and is used by the ECU to determine boost, but it's an absolute measurement. Your gauge is relative to atmosphere so the readings will differ by whatever the atmospheric pressure is at the time.

 

It's usually your driving style.

 

Sup guys, here's a thread in Hawaii about Gas Mileage Survey!! Check it out guys. Hope this helps.

https://www.i-club.com/forums/hawaii-43/gas-consupmtion-survey-133156/