In addition, colder outside temperatures can cause gas to combust more or less efficiently, changing the makeup of the exhaust. As you may know, gas formulations change between winter and summer in many regions, and this can cause the vehicle emissions to change.
One reason for the P0420 code can be when the gas stations switch over to winter blend gas. Reason 1: Gas Blend, Outside Temperature, or “Bad Gas” If you are getting a P0420 error code (and only the P0420) repeatedly, then you likely have one of the following problems. These are the Most Common Reasons for a P0420 Code Also, check the regulations in your state concerning illuminated check engine lights, as the vehicle may not pass inspection with the CEL lit. Keep in mind that if you leave the P0420 error code, then you check engine light will constantly be lit which could potentially make it so that you miss any other error codes that may come up in addition to the P0420. It relates more to the efficiency (or monitoring) of the exhaust recovery system. The other thing to ask yourself is, “Self, can I live with this error and constant check engine light?” The P0420 is generally not a safety issue in terms of the car being unsafe. This list is ordered roughly from easiest/most likely to most difficult/expensive. When fixing a P0420 error code, start with the easiest and least expensive solutions, before progressing to the more difficult and expensive solutions.
How to Fix a P0420 Error Code on a Toyota Corolla
The way the vehicle determines that the catalytic converter is working okay is by measuring the oxygen content of the exhaust both upstream and downstream of the catalytic converter. If you’re not sure how to do this, read this post on how to read engine codes.Įrror codes that start with P042-, refer to a problem with the catalytic converter (cat). Use an ODB2 check engine light reader to read the error codes that are causing your check engine light (CEL) to illuminate. Diagnosing a Check Engine Light Caused by the P0420 Error Code When you buy through links on our site, we may earn an affiliate commission – at no cost to you.
Are you getting the dreaded P0420 error code from your Toyota Corolla? This post discusses the reasons for the code, and the easiest way to fix this common problem.