Efficiency Definition - AutoZone Glossary

These trouble codes are both signs of catalyst efficiency problems. Learn what can cause these codes, and what to do about them.

Seeing P0421 on your code reader? Learn some common causes and solutions to the problem.

Which one's better depends on what you're looking for. Learn the pros and cons of each system.

Forced induction can add a lot of power to an engine. Learn more about turbos and superchargers.

Ever wonder about the history of fuel injection? Us too. Check out how cars moved from carburetors to electronic fuel injection.

Seeing P2004 when you check your codes? Learn some common causes and solutions to this error.

Reading P0135 on your code reader? Learn what causes this issue and what you can do to fix it.

Reading P3400 on your scan tool? Check out some common causes and solutions to this problem.

Seeing P0420 on your code reader? Learn some common causes and solutions for this issue.