Weird noise when accelerating
- Thread starter cander31
- Start date
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whtbronco
Full Access Members
The code indicates the bank 1 catalytic converter is getting plugged up or worn out. That signal comes from the downstream O2 sensor so a failing sensor can trigger the P0420 code, but would not cause a noise. You'd have to decide what the noise sounds like to determine if it could be a cat that's nearing the end of it's useful life. I've heard of cats coming apart, but never experienced it so I can't say what that would sound like.
Has your fuel economy dropped or are you burning a lot motor oil?
This is not likely the result of timing issues in my opinion.
Has your fuel economy dropped or are you burning a lot motor oil?
This is not likely the result of timing issues in my opinion.
SafariGoneWrong
Full Access Members
Agree with @whtbronco. The P0420 is usually definitive—the cat is bad and it could range from the cat being polluted (Kia Soul owners) to the substrate coming apart. Not often it’s the downstream O2 sensor. The only reliable way to determine if it’s come apart internally is either full or partial removal. My Bronco’s came apart internally but no noise, only reduced power. My Soul’s simply gave up. Your noise isn’t VCT related.
