Posts Tagged: P0420
A DIYers guide to the dreaded P0420 catalytic converter code
What to do when you get a P0420 catalytic converter code If you’ve got a check engine light with either a P0420 P0420 catalytic converter code or a P0430 trouble code, don’t automatically replace the oxygen sensor. Why? Because a herP0420 catalytic converter code is almost NEVER caused by a bad oxygen sensor. Here’s a step by step guide to dealing with a P0420 or P0430 code Why it’s never the oxygen sensor Here’s how the computer tests the efficiency of your catalytic converter. Once it’s up to operating temperature, … Read More
What causes catalytic converter failure and P0420
Causes of catalytic converter failure and P0420 A P0420 trouble code Catalyst System Efficiency Below Threshold (Bank 1), and P0430 Catalyst System Efficiency Below Threshold (Bank ) usually mean you’ll be in the market for a new catalytic converter. A P042o or P0430 is almost never a bad oxygen sensor Yes, I know that many online sites tell you to fix a P0420 with a new oxygen sensor. In rare cases, that might fix the problem. But for the vast majority, replacing the oxygen sensor is really wishful thinking and … Read More
Fix Code P0420
Fix Code P0420 A P0420 code means your catalytic converter has failed an efficiency test. In other words, it’s not removing harmful combustion byproducts from the exhaust. Many people think that the way to fix code P0420 is to replace the oxygen sensors. That’s wrong. In fact, the vehicle computer can’t even come to the conclusion that your catalytic converter has failed the efficiency test if your oxygen sensors are bad. So don’t waste your time and money on oxygen sensors. What to do if you get a P0420 code? … Read More
Toyota Scion P0420
Fix code P0420 Toyota Scion If you own a 4-cylinder Toyota or Scion vehicle and get a check engine light with trouble code P0420, welcome to the club. This has been a persistent problem with these vehicles. To get right to the point, the problem is bad software. Toyota has updated it. But that’s not all. If you don’t maintain this vehicle EXACTLY as Toyota says, you can accelerate this problem. It all starts with misfires and not changing your oil. Misfires send unburned fuel down into the catalytic converter where it’s … Read More
P0420 Catalyst System Efficiency
P0420 Catalyst System Efficiency Below Threshold (Bank 1) Code P0420 Catalyst System Efficiency Below Threshold (Bank 2) NOTE: Codes P0420 and code P0430 are similar. I wrote a much more detailed explanation of how an emission system works and what causes these codes. Read this post and then refer to this more detailed post. Code P0420 means the catalytic converter for bank 1 has failed it’s testing. The oxygen sensor in front of the catalytic converter switches back and forth between rich and lean as the computer constantly changes air … Read More