You can quickly diagnose any Check Engine or Service Engine Light with your Smart Phone and an OBD2 reader while your engine is running. These new devices cost much less than the standard code readers allowing you the security of knowing first hand what the problem is and not worrying about being taken advantage of. With this book you can identify the part and know first hand what the part looks like for your car. Most Check Engine problems can be fixed easily. Check Engine or Service Engine indicator will require a replacement of some part. However most of these parts are easier to replace than you may think. The difficulty can be determined by how small or large the engine compartment is and the removal of shields and covers. Of course trucks will be the easiest to work on. The time it takes to actually remove and replace most of the parts can range from 5 to 20 minutes.