PONTIAC G5 WARNING LIGHT

Recently We Replaced The Engine (2.2l Ecotech), From Another 2008 Pontiac G5 With The Original Engine That Blew A Had Gasket. All Went...

Check Engine Light Came On And Brought It Into Mechanic Who Scanned And Said The Rpm's Were Going Crazy. Idle Was Rough And Sounded...

If I Have Replaced The Sensor In My Pontiac G5, And The Engine Light Is Still On And Coolant Is Reading.(No Temp.) What Should I Do Next If...