I have a 2005 trailblazer LT. 4.6 motor. One day it started running really bad. We had some -50 days and it ran fine and I away let it idle for 10 min before taking off and was really easy on it. I drove it to work last Thursday had no issue. When i started it to go home notice it wasn't running right put into gear and it would go into limp mode and die. The dash said low oil pressure I did have a full tank of gas and did put heat in 3 days before this started happening. I notice if I let it idle i have liquid coming out of the exhaust. i think it's unburnt fuel but not sure. Not sure where to began with trouble shooting. I check all fluids and they all look good. If i'm in neutral and go above 2000 rpm then it will go into limp mode and die.