I get 14 to 15 MPG around 3400 ft when I get into the mountains of Colorado I get around 19 MPG, no I'm not resetting going down hill. at 3400 ft the absolute pressure is showing 26 when the weather service is reporting 30.6 this is with the jeep shut down with the dealership data logger hooked up to the jeep. they replaced the mapp sensor or (absolute pressure sensor) other than cracked exhaust headers. this shouldn't affect the sensor reading while its shut down. Any idea what could cause the sensor to read so far off? The engine hesitating and dying at a take off. Dealership didn't know about the cracked header until I researched the problem and ask them to check under the heat shield. what is the range of the absolute pressure sensor (hi N low readings) under the hood (engine compartment gets real hot)any additional information would be a great help.