Hello, looking for advice on engine behavior. 1997 360 with 150,000 three months ago started using two quarts between changes (was 1/2 qt). It is not smoking or leaking any oil, coolant is clean and green. Check engine light came on, started running rough, loss of power, surging. Then is would run fine for several days and the warning light would go out. Then is would happen again and the cycle time between occurrences is becoming shorter. Took it to a Dodge dealer for diagnoses. They said the intake gasket is leaking and allowing it to suck in oil, probably damaged the oxygen sensor. And they want $1300 to fix it. Has anyone else had this issue, or believe what they are saying? If it is the intake gasket and ox sensor, I can replace them myself.