Check Catalytic Converter with Scan Tool: How To Guide


First, check if your vehicle’s check engine light is on after ignition, the initial step towards diagnosing the problem. You can then use an OBDII scan tool to determine why the check engine lamp is on.

How to Use a Scanner to Check Your Catalytic Converter

Step 1: Connect the scanner connector to the OBDII port located on the left side of your steering wheel.

Step 2: Start the machine and let it run for 10-15 mins to raise the temperature.

Step 3: If the scan tool returns code P0420, then there may be a problem in your catalytic converter.

Step 4:  Access live data from your sensor

Step 5: Click the O2 (oxygen sensor data) button

Step 6: A problem is in sight when the O2S12 sensor fluctuates between very high and very low.

The Best Catalytic Converter Scan Tools

Are you lacking a scanner? These are the top three options available.

1. ANCEL Universal OBD II Scanner

This is the most economical option and offers the best value for money. This unit is easy to use but has many advanced features. It can diagnose trouble codes for engine lights, identify malfunctioning indicator lamps, perform monitor readiness testing, and has an LCD screen. The cable is 2.5 feet long, so you can connect it to most vehicles with older models.

2. Autel Autolink

The Autel Autolink AL519 scanner is designed for intermediate users. The tool is straightforward to use and can diagnose generic, manufacturer-specific, and pending trouble codes. You can use it to turn off the check engine lights and reset monitors, and it is the most popular Autel product in the scanner sector.


This OBD2 scanner is a leader in the scan tool area. Compatible with all 1996-2013 GM and Ford, Hyundai, Toyotas, Nissans, Chrysler, Honda, and Chrysler vehicles. The tool is advanced and costs approximately $300, designed for regular vehicle diagnostics, reading diagnostic trouble codes, graph engine data, record and playback stored vehicle information.

Temperature Gun for Cat Converter

You can use modern temperature guns to point the laser beam directly at the converter, reducing the need to drive holes in the converter.

Simply measure the temperature at the converter’s front and back. The area where the air enters the converter should be warmer than that at which it exists. The temperature readings at the entry point and exit points should be higher than those at the exit. The text should be identical, indicating that chemical reactions are not occurring and the converter is not performing its job.

The AstroAI Digital Laser Infrared Thermometer is one of the most reliable temperature guns to test a catalytic convertor, and you can use it to measure temperature in Celsius and Fahrenheit degrees. The tool works by aiming and pressing; its temperature range is between negative 58 degrees Fahrenheit and positive 1022 degrees Fahrenheit. It uses a 9-volt battery as its power source.

Last words

You can use the OBDII scan tool can to test, diagnose and fix a catalytic


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