The meaning of the U2003 Code is necessary to know but before that make sure that you know the correct meaning of the engine. The general meaning of the engine code is not helpful. The engine code U2003 OBD2 reports a sensor problem, extra of the sensor is improbable to solve the original problem. The fault is the most probable to be produced by the systems that the sensor is checking but might even be caused by the cabling to the sensor itself. If you want to know anything else about the car engine, you can check online but reading the car engine manual is very good idea.