This book, "Make Your Own Diagnostic Equipment?", came about from the need of many readers and viewers to be able to make and maintain fairly simple diagnostic gadgets. It is meant to show and guide the professional technician and DIY mechanic on how to make these gadgets. In many cases, due to the nature of the equipment industry, it is very expensive or virtually impossible to get these tools. The reason being is that often times tool makers don't see a profit in making these simple but effective gadgets. Most, if not all of these tools, are invaluable in diagnosing modern automotive systems. You can estimate that having one of these tools, at the right time when needed, will cut your diagnostic time by at least 50%. Of course, knowing how to use it is also important. However, by definition if you've already studied how the gadget works, how to build it an also ended up building it yourself, you've already passed the learning curve and chances are you'll know how to use it. At the very least, reading this book will put you in a much better position to also asses diagnostic issues and on the use of other important tools of automotive diagnostics. It is our hope with this work to enlighten the professional and DIY mechanic on the use, construction and operation of modern automotive diagnostic gadgets. Use this information to the beast of your abilities and be on the diagnostic driver seat. Table of Contents * O2 Sensor Simulator * Using the O2 Sensor Simulator * ABS Speed Sensor Simulator * Using the ABS Speed Sensor Simulator * ABS Speed Sensor Simulator, Bleeding the Brakes * Optical CAM and CRANK Sensor Simulator * Using the Optical CAM and CRANK Sensor Simulator * OBD-2 Data Link Connector Breakout Box * Using the OBD-2 DLC Breakout Box.