The P0420 OBD2 code indicates that the efficiency of the catalyst system is below the threshold. But that doesn’t necessarily mean you have a bad catalytic converter.
The code will happen if the upstream and downstream oxygen sensors indicate similar readings. They won’t match if the catalyst system is within a proper threshold.
The car’s performance is only affected if the catalytic converter is extremely clogged, reducing fuel efficiency. You’ll feel it because it will be as if you have a clogged fuel filter, and the engine will tend to stall out under heavy loads.
I have a 1996 cadillac fleetwood and the check engine light comes on and stays on for a period of time, then goes out. But it comes back on after a some time. I was told that it was an indication that my catalytic converter was going bad. The last time I filled up with gas the light was out. Should I replace the catalytic converter although the light is out at this time?
I just had my catalytic converter changed as it was bad as it had all the symptoms (bad fuel consumption, loss of power, problem shifting gears, etc) since I got it replaced the car runs perfect like it did when I first got it. Though after driving it for 50 some odd miles the check engine light came back on and is showing the code for low efficiency. Is my car's new catalytic converter bad or could it be that the o2 sensors need to be changed?
Copyright © 2020 HubPages Inc. and respective owners. Other product and company names shown may be trademarks of their respective owners. HubPages® is a registered Service Mark of HubPages, Inc. HubPages and Hubbers (authors) may earn revenue on this page based on affiliate relationships and advertisements with partners including Amazon, Google, and others.
HubPages Inc, a part of Maven Inc.
|HubPages Device ID||This is used to identify particular browsers or devices when the access the service, and is used for security reasons.|
|Login||This is necessary to sign in to the HubPages Service.|
|HubPages Traffic Pixel||This is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.|
|Remarketing Pixels||We may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.|
|Conversion Tracking Pixels||We may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.|