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Ron Z.
Ron Z., - Cadillac Tech -
Category: Cadillac
Satisfied Customers: 17788
Experience:  18+yrs experience. State Inspector and Cadillac Diagnostics
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We are getting an sporadic P0480 code. sorry, it's a P0420

Customer Question

We are getting an sporadic P0480 code.
JA: Just to clarify, what's the exact code? And have you tried to reset it?
Customer: sorry, it's a P0420 code
JA: What is the model/year of your Cadillac?
Customer: 2010 SRX and that is the exact code. I can clear it, but it comes back after a few weeks or a few days.
JA: Are you hoping to fix this yourself? What have you tried so far?
Customer: yes, looking to fix it my self. only done a little internet research so far. heard it could be the actual cat or might just be a worn gas cap messing up the readings. it does seem to throw the code more often after filling up
JA: Anything else you think the mechanic should know?
Customer: no
Submitted: 2 months ago.
Category: Cadillac
Expert:  Ron Z. replied 2 months ago.

Unfortunately, the P0420 is a fairly straight forward code, and a fairly common problem. This code points to a failing Catalytic Converter (for Bank1). The Oxygen Sensors measure the amount of emissions in the exhaust going into, and then out of the converter. When they see that the converter is not "cleaning" the exhaust enough to meet specs, the Converter is deemed "below threshold" and the P0420 is set. Make sure there are no current cylinder misfires. Make sure there are no leaks in the exhaust system. Which, if there were, you should be able to hear. Sounding like a repeating "tick" or "puff" from the exhaust. Usually more prodominate when the engine is cold. Make sure to include the exhaust manifold when checking for leaks/cracks. If these check ok, then most commonly, the Converter is "on it's way out" and will need replacement in the near future. Keep in mind, you will need a replacement converter that meets specs. Those "universal" or "discount" converters sold at some after market parts stores do not meet specs, and will not cure a P0420. The Bank1 Converter is located on the side of the engine closest to the windshield. If you found this answer helpful, please help me by leaving a rating using the "stars" at the top of the page or click 'accept'.
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Expert:  Ron Z. replied 2 months ago.

If there are any other questions you had on this, or you'd like an estimate for repair... please feel free to reply and ask!

Expert:  Ron Z. replied 2 months ago.

Hi! I noticed this thread was still open and you did not leave a rating , so I wanted to check in and see if there was anything else I could do for you on this issue? Did you have any other questions? Was there something I missed that you wanted addressed? If you have no further questions and simply forgot to leave a rating, please take a second and use the stars at the top of the page to rate our Q&A session. Thank-you!