What does a dead catalytic converter looks like?
#1
02-26-2009, 09:36 PM
Join Date: Mar 2008
Location: Sunnyvale, CA
Posts: 155
Rep Power: 33 
What does a dead catalytic converter looks like?
Hi there,
I've had a P0420 a few times. I was about to call it a bad O2 sensor when I was told to look at a plot of the O2 sensor voltage pre and post cat. That would rule the sensor vs. the cat.
Just in case any of you is wondering what it should and shouldn't look like.
See for yourself:
Bank 1 is the "bad cat", ahah.... Basically a pass-through where the post sensor reads the same as the pre. Meaning that nothing get's done. Nada!
Bank 2 shows the "good cat", Where the post is nice and flat, showing the cat is oxydizing nicely and does what it is supposed to do.
Plots done using Durametric USB Cable
My car is a 2002 C4S, 7 years warranty on the catalytics. That will have to be paid for by Porsche
(Sorry if this is a repeat but I couldn't find this easily so figured I would share again)
I've had a P0420 a few times. I was about to call it a bad O2 sensor when I was told to look at a plot of the O2 sensor voltage pre and post cat. That would rule the sensor vs. the cat.
Just in case any of you is wondering what it should and shouldn't look like.
See for yourself:
Bank 1 is the "bad cat", ahah.... Basically a pass-through where the post sensor reads the same as the pre. Meaning that nothing get's done. Nada!
Bank 2 shows the "good cat", Where the post is nice and flat, showing the cat is oxydizing nicely and does what it is supposed to do.
Plots done using Durametric USB Cable
My car is a 2002 C4S, 7 years warranty on the catalytics. That will have to be paid for by Porsche
(Sorry if this is a repeat but I couldn't find this easily so figured I would share again)
#3
02-26-2009, 09:44 PM
Join Date: Mar 2008
Location: Sunnyvale, CA
Posts: 155
Rep Power: 33 
I only have Bank 1 dead for now. Problem is: I cleared the code again so I have to wait for it to come back before I bring it to the stealer for a warranty job.
I was told by my trusted independant Porsche mechanic that it will come back when driving nice and easy around 2000rpm for long enough... This is hard to do!!!
#4
02-27-2009, 05:28 AM
Hmmm... I didn't work all that hard to make mine pop on. Then again, maybe my cats were in worse shape. Either way, it'll come back. Anything that is warranty related should be left on the dash. No harm in reading it, but I wouldn't clear it.
#5
03-25-2009, 05:50 PM
Join Date: Mar 2008
Location: Sunnyvale, CA
Posts: 155
Rep Power: 33
Just to close the loop on this. I finally brought my car to the dealer and they confirmed Bank 1 was dead and while they were at it, claimed that Bank 2 had some loose substrate and changed it too...
So here I am with a 7 years old car and TWO brand new catalytic converters courtesy of PCNA and the State of California... thanks guys!
So here I am with a 7 years old car and TWO brand new catalytic converters courtesy of PCNA and the State of California... thanks guys!
#7
03-28-2009, 11:08 AM
Join Date: Mar 2008
Location: Sunnyvale, CA
Posts: 155
Rep Power: 33
I believe Bank 1 is the driver side cylinders/catalytic (passenger side muffler)...
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#9
06-21-2009, 02:43 AM
Join Date: Mar 2008
Location: Sunnyvale, CA
Posts: 155
Rep Power: 33 Mine was 70,000miles/7years . I believe the new ones now are 80,000miles/8years
Good luck!
#10
10-21-2010, 03:38 PM
Registered User
Join Date: Oct 2009
Location: Moorestown, NJ
Posts: 2,202
Rep Power: 260 
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