P0420 after replacing Cat and both O2
Professional
Joined: Sep 2011
Posts: 136
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From: Oregon
Just saw this on a Mazda site:
Do you buy it?
Oil consumption can be an effect of a PLUG not firing too! That is to say the MISFIRE, doesn't expand the piston rings to seat them and can lead to a single hole moving oil.
Professional
Joined: Sep 2011
Posts: 136
Likes: 0
From: Oregon
Well, that may be for some, but this thing still does the same thing even with new Champions. Let it idle for a few minutes and when you take off you get a plume of oil smoke.
Professional
Joined: Sep 2011
Posts: 136
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From: Oregon
Tizzy, are you saying that we likely have stem seals leaking? If I pull the front valve cover will I be able to see the seals through the springs and do they typically fall apart? You also mentioned dropping the valve guides on earlier engines. Does that mean they fall out, or just slip down enough that the seal falls off?
Champion
Joined: Jan 2010
Posts: 3,023
Likes: 5
Must of missed my earlier, earlier post. My money is that A. - you have worn valve seals, and no, you can't verify visually. And B - most likely you have a tapered cylinder bore which will cause the piston ring gaps to line up causing oil to be sucked though. Nothing a valve job and short block won't cure!! You can have a cylinder leak down test done, let you know how the rings are anyway.
Registered User
Joined: Jul 2013
Posts: 5
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Not sure what brand name O2 sensors you installed on your customer's van. Replace the O2 sensor with OEM Mopar ones, the code must go away.
It happens all the time like your situation, new aftermarket O2 sensor trigger Check Engine light
It happens all the time like your situation, new aftermarket O2 sensor trigger Check Engine light
Hi folks, I'm a mechanic that is banging my head against a wall with two 2006 minivans. Both with 3.8L one a Grand Caravan and the other a Town and County. Replaced Catalytic Converter on both and replaced both (upstream and downstream) O2 sensors with NGK O2 sensors on both vans. I'm stumped with this one. Code comes back on both vans all the time. So much so that the Grand Caravan has the code set on the scanner but check engine light has become randomly on and off.
Anyone else out there seen this with the 06? or at all? I have no idea what to do on these and the dealer is being no help at all.
Thank you in advance,
ajcasper
Anyone else out there seen this with the 06? or at all? I have no idea what to do on these and the dealer is being no help at all.
Thank you in advance,
ajcasper
