Hey guys, I own a 2011 Chevy Malibu with 162K miles. I recently got a code for P0420, I was wondering if I could replace my downstream 02 sensor and use a bottle of cataclean to fix my issue? I’ve also checked my downstream o2 sensor and it sits at around .84 V
You might want to check the other conditions that can trigger that code.
https://www.walkerexhaust.com/support/tech-tips/diagnosing-catalytic-converter-p0420-code.html
https://www.carparts.com/blog/p0420-code-catalyst-system-efficiency-below-threshold-bank-1-2-2/
https://www.obd-codes.com/p0420
@chucktobias I’ll have to check my spark plugs, I did replace them maybe half a year ago with Ruthenium plugs
@g-t So I did check my spark plugs and they’re not burning oil. The whole tip isn’t sludgy or black
What about the exhaust tailpipe. Is it oily or just soot?
https://carkiller.com/scottykilmer/postid/1049/
I got that on my 2005 pontiac vibe. I first cleared the code to see how bad it was, code didn't come back for 6 months. It isn't burning oil, no other issues I can detect. I have seen the code 2 times within 10k miles+.
I am not messing with it much unless the code becomes persistent.
