The health of your car’s engine and other major components is monitored by a system called On Board Diagnostics, or OBD. When the system detects a problem it sends error codes to the best obd2 scanner for gas and diesel and an onboard computer that records them. These errors are accompanied by the Check Engine light, or CEL, which illuminates when the OBD system has detected a potential problem. A specialized “scan tool” is needed to decipher these error codes, which are actually five-place alphanumeric designations like P0420 (catalytic converter operation), and turn off the CEL once they’re resolved.
Today, do-it-yourselfers can pick up a low-cost OBD scanner from just about any major car parts store and have the tools they need to fix problems themselves at home. Some of these consumer-priced models do things that were reserved for $5,000 pro-grade scanners just a couple of years ago.
There are many different types of scanners available, with varying features and capabilities. For do-it-yourselfers, the most important is the ability to read and clear engine codes (to keep the check engine light turned off). Other more advanced features are useful only if you have some mechanic know-how or if the vehicle in question has specific systems that require a more specialized scanner, such as ABS.
Beyond basic code reading and smog test reading, it’s important that your best OBD2 scanner for gas and diesel can also show you a Freeze Frame, a rundown of the key data points in a car at the moment a check engine light is triggered, to help pinpoint what’s wrong. Also, make sure your scanner can access software updates from its manufacturer — a good brand will do this regularly, often for free.