Error Code P0420

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Jun 17, 2007 | 03:29 PM

#46

Bluegrass 7

Lead Driver

Joined: Sep 2006

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He was given expert advice by several people but continues to try to evade.
Here it is in a different format.
The cats are coated on a ceramic substrate with rare earth metals that clean the exhaust once they are heated to over 600 degrees temp.
The front Ox sensor has nothing to do with the cats but controls the fuel according to the ox found in the exhaust gas.
The rear ox sensors send there signals to the PCM where it's action is compared to the front sensor "only". The rear is not supposed to vary it's output but very little in compairison.
IF IT does, it is detecting varying OX level indicationg the cat IS NOT cleanig up.
What else do you need to know?
Any other sensor faults are detected by the PCM and have their own codes.
Another way to possibly get supporting diagnostic info is reading the case Temp of the cats on each side and compairing. Any significently cooler case temp means that cat is not processing as it should.
I'm sorry if your not happy with this reply but I call as I see it!

Jun 17, 2007 | 04:34 PM

#47

chevsucks

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Joined: Apr 2007

Posts: 7

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hey thanks daddyd5150 you know nothing is more agrivating than not knowing what to start looking for i was about to start buying things like coils cause ford said it could be that but it seemed kind of odd that all 4 coils on that side could go all at once but i think i'll start with the cat. and or o2 sensor before cat. and so thanks alot and did you know that Dustin Penner #17 of the anihiem ducks comes from my home town .

Aug 30, 2007 | 12:57 AM

#48

freerange

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Joined: Jul 2005

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Error code checking

I found a handy site and device that hooks into a personal computer and provides a lot of information on error codes. It can be found at http://obddiagnostics.com/index.html

It works great.

JC

Jul 1, 2014 | 05:25 PM

#49

coopa

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Joined: May 2014

Posts: 1

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auto zone and Advance AP

Quote:

Originally Posted by Munky

Alright, bad gas was something that both Advance Auto and Auto Zone both told me that it could be. Is there a way other than taking the truck to the dealership that I can tell if it's the cat, something I can do on my own at home?

Both of these stores (and others) can read the codes, but whether anything they tell you beyond that is useful, it is a crap shoot. I've developed a relationship with a couple of Auto Zone workers who have considerable experience as dealership techs. They've been very helpful to me. But with many of these counter men (and women) they just don't know what they don't know.

Forums like this one are also excellent, but in their desire to be helpful, or funny, some posters offer bad information and bad jokes. You just have to do the research and weigh the information carefully, then proceed.