When the check-engine light snaps on, it is not a suggestion, it is your car’s way of saying something in the powertrain or ...

️ Editor's note: This product category requires new testing about once a year. We'll update this article with the most recent information when it's available. Modern cars are technological marvels, ...

We may receive a commission on purchases made from links. If you own a car built in 1996 or later for the U.S. market, the odds are overwhelming that it has an OBD port. You may have even noticed its ...

The world of car diagnostics has changed a lot over the last 50 years. Back in the '70s and earlier, a mechanic's most valuable diagnostic tools were usually their eyes and ears. You could figure out ...

We may receive a commission on purchases made from links. If you've ever connected a standard OBD-II scanner to your motorcycle only to find it doesn't work as expected, you're not alone. Unlike cars, ...

OBD II requires that a vehicle's computer system indicate when components have failed, resulting in the emission of pollutants at 1.5 times the accepted level. Another requirement of OBD II is that ...

Automotive diagnostics have come a long way since the “idiot lights” of the 1980s. The current version of the on-board diagnostics (OBD) protocol provides real time data as well as fault diagnostics, ...

In 1976, Chrysler ushered in the computer engine management system era with their Electronic Lean Burn 400 4-bbl. This early computerized spark-advance control system was developed to make the engine ...

This article was updated in November 2025 with new information. You know you’ve earned your DIY stripes when you can stay calm the moment something goes wrong. And with cars, that moment usually ...

Seeing your vehicle's check-engine light come on can throw a wrench in your travel plans. It can also feel a little scary: Does it mean your ride is headed for the scrapyard? Or is there a simple fix?