96 LT Shuts Off

Ok here's my newest problem. Driving home from work today I noticed what seemed to be a hesitation and loss of power. Well after about six miles I heard what sounded kinda like a small backfire but it seemed to come from under the hood. Going up a hill I lost all power. Pulled over and stopped. Restarted fine and even kept running when I shifted from park, but..... the minute I stepped on the gas it died. Restarted and the same thing happened again. Checked all my hoses and lines thinking maybe something came unplugged and everything was just the way it should be. I tried one more time and it fired up but the idle seemed to be only about 500 rpm. Put it in gear and it still ran but again as soon as I shift out of park the same thing happened again. ANy ideas guys???????

Went and hooked upmy scan tool and got a MAF code. Sensor is less than a year old. Could the oil from the K&N filter have harmed the sensor?