Catalytic Converter

An automotive exhaust-system component, made of stainless steel, containing a catalyst to reduce oxides of nitrogen (NOX), and/or hydrocarbon (HC), and carbon monoxide (CO), in tailpipe emissions.

What Black, Blue, or White Smoke from a Car's Exhaust Means

Smoke from the exhaust pipe can mean a few different things depending on the color of the smoke. Learn what to look for so you can figure out what is wrong.

Man looking at his Mustang in the garage and wondering

How to Find and Fix Exhaust Leaks

It's always a good time to do something about that exhaust leak. Learn common places these leaks occur as well as methods for finding and fixing them.

P0420 and P0421: Catalyst Trouble Codes

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

P0421: Warm Up Catalyst Efficiency Below Threshold

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

P0303: Cylinder #3 Misfire

Seeing P0303 on your code reader? Learn some common causes and solutions for this error code.

AutoZoner using Fix Finder scan tool to diagnose P0401

P0401: Insufficient EGR Flow

Seeing P0401 on your code reader? Learn some common causes and solutions to this problem.

AutoZoner consulting his OBD reader and attempting to determine how to fix code p0136

P0136: O2 Sensor Circuit Low Voltage (B1S2)

Just ran an OBD scan and got P0136? Find out common causes and solutions.

P0304: Cylinder #4 Misfire

Seeing P0304 on your code reader? Learn common causes and solutions.

P0420: Catalyst System Efficiency Below Threshold

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