My check engine light slowly came on relating to my gas cap over several months and after a while stayed on. After it didn't start up right once, I took it to a mechanic who read the engine error and said there were two errors both relating to replacing the Mass Airflow Sensor. He'd fix it for $400 and that it was something that was easy to do yourself. I did it myself and it was easy and the part only cost $30. Upon completing that however, my EPC light turned on. It runs a touch smoother now but I don't think its getting the power it should be because I'm slowly reverting back to having a more difficult time starting the car which I've never had before the one time. Thanks for your help.