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code p0420 and p0420b

Posted: Wed Dec 07, 2011 10:32 am
by 2ZZGE
I buy vibe gt from woman than have it since 5 year and never put 91 octane in it...only 87 octaneI buy it with cel light on and run about 2 tanks of 91 octane and the light close off without reset...now I take the trouble code and read p0420 and p0420b store in memoryCan i need change 02 sensor or catalytic...both... or never mind if cel don't light against?is it normale trouble when use 87 octane on 2zz-ge?

Re: code p0420 and p0420b (2ZZGE)

Posted: Wed Dec 07, 2011 12:36 pm
by A Psycho Martyr
if the check engine light stays off, i wouldm't worry about iti got that code 40k miles ago still no trouble

Re: code p0420 and p0420b (2ZZGE)

Posted: Thu Dec 29, 2011 9:50 am
by bh357
I drove for a whole lot of miles with my CEL on and a P0420 code stored. Ended up replacing the cat, and no CEL since (knock on wood).

Posted: Fri Dec 30, 2011 3:10 am
by DiveNut
99% of the time it is a bad CAT. Mine threw an occasional P420 which I cleared on/off for a few years before it finally stayed on. Replacing the CAT fixed it.