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2006 chrysler 3.5 300 #4621560
01/02/18 11:09 AM
01/02/18 11:09 AM
Joined: Feb 2009
Posts: 59
ny
jeep58 Online content OP
jeep58  Online Content OP
Joined: Feb 2009
Posts: 59
ny
Hi I have this car with 75k on it got it from original owner, the code P0420 came on I reset it with scan tool. it will come on again the car uses oil in between oil 3.5 engines are know for that. The car has plenty of power so cats are not completely clogged. Why would the cat be going so soon and has anyone with this engine 3.5 had the same problems?

Re: 2006 chrysler 3.5 300 [Re: jeep58] #4621585
01/02/18 11:34 AM
01/02/18 11:34 AM
Joined: Nov 2011
Posts: 4,857
MTL, CANADA
Rolla07 Offline
Rolla07  Offline
Joined: Nov 2011
Posts: 4,857
MTL, CANADA
http://www.p0420.com

Check for holes in exhaust pipe, 02 sensor etc.


2007 Corolla Red Pearl 155k miles
PP 0w20 & ST 4967

Re: 2006 chrysler 3.5 300 [Re: jeep58] #4621777
01/02/18 02:29 PM
01/02/18 02:29 PM
Joined: Feb 2009
Posts: 59
ny
jeep58 Online content OP
jeep58  Online Content OP
Joined: Feb 2009
Posts: 59
ny
I have a friend that owns a garage the system is all stainless steel no leaks, I know theses engines use oil just wandering if that is the cause of the check engine light coming on!

Re: 2006 chrysler 3.5 300 [Re: jeep58] #4621911
01/02/18 04:50 PM
01/02/18 04:50 PM
Joined: Sep 2007
Posts: 968
TX, USA
JMJNet Offline
JMJNet  Offline
Joined: Sep 2007
Posts: 968
TX, USA
P0420 is usually O2 sensors, there are usually sensors before and after the cat.
Depending on the engine there may be 2 before and 2 after.
At least that was my experience with the Toyota.

You may need to check the forum specific for your car manufacturer to check with their experience fixing this code.

BITOG is more of a generic forum for this type of issue.

Last edited by JMJNet; 01/02/18 04:53 PM.

  • 2017 Toyota Sienna
  • 1995 GMC Suburban 6.5L Turbo Diesel


Re: 2006 chrysler 3.5 300 [Re: jeep58] #4621941
01/02/18 05:20 PM
01/02/18 05:20 PM
Joined: Jan 2016
Posts: 321
Kansas
ejes Offline
ejes  Offline
Joined: Jan 2016
Posts: 321
Kansas
As said previously, likely an O2 sensor. Some say to replace them all at once if you can, some say just replace them as they go bad. If I can find them all fairly cheaply, and its on a car/truck with a lot of miles or age, I do them all when one fails. I've had good luck with Denso and NTK. I believe the 06 300 V-6 gas 2 upstreams and 2 downstreams and they are all the same model of sensor. You can get NTK's for 25 bucks at RA.

Re: 2006 chrysler 3.5 300 [Re: jeep58] #4621942
01/02/18 05:23 PM
01/02/18 05:23 PM
Joined: Feb 2009
Posts: 59
ny
jeep58 Online content OP
jeep58  Online Content OP
Joined: Feb 2009
Posts: 59
ny
Ok Thanks there are 2 sensors on the cat one before and one after any idea as to which one could be bad?

Re: 2006 chrysler 3.5 300 [Re: jeep58] #4621959
01/02/18 05:44 PM
01/02/18 05:44 PM
Joined: Jan 2016
Posts: 321
Kansas
ejes Offline
ejes  Offline
Joined: Jan 2016
Posts: 321
Kansas
Inspect them first for loose or broken wires, etc. I generally suspect the downstream first, but the only way to really tell is with a scan tool that tells you. Some do and some don't. Sometimes AZ and other auto parts places will scan it and tell you if you buy the part there. There are ways to test them with voltmeters, etc. if you google it.

Re: 2006 chrysler 3.5 300 [Re: jeep58] #4622008
01/02/18 06:28 PM
01/02/18 06:28 PM
Joined: Mar 2012
Posts: 804
BerksCounty/Pa.
thorromig Offline
thorromig  Offline
Joined: Mar 2012
Posts: 804
BerksCounty/Pa.
My good friend a head mechanic at a Cadillac dealership says "always" use OEM O2 sensors when replacing them.


00 Dodge Ram 5.2L 4x4 Edge 10W30 FU (91K)
08 Acura TL Type S 3.5L PUPP 5W20 FU (101K)
17 Jetta TSI SE 1.4L Turbo - Edge 0W40 FU (Hers) (4K)
Re: 2006 chrysler 3.5 300 [Re: jeep58] #4622012
01/02/18 06:35 PM
01/02/18 06:35 PM
Joined: Nov 2016
Posts: 1,278
WI
HoosierJeeper Offline
HoosierJeeper  Offline
Joined: Nov 2016
Posts: 1,278
WI
Only use NTK on anything Mopar! O'Reillys carries them.


15 Jeep KL Limited V6: Formula Shell 5W20
07 LR3 SE V8: Maxlife 5W30
05 Jeep KJ Limited: PHM 5W30
96 Jeep XJ Country: STP HM 5W30 (winter)
Re: 2006 chrysler 3.5 300 [Re: jeep58] #4622051
01/02/18 07:18 PM
01/02/18 07:18 PM
Joined: Dec 2013
Posts: 2,190
Fort Worth, Texas
clinebarger Offline
clinebarger  Offline
Joined: Dec 2013
Posts: 2,190
Fort Worth, Texas
Swap the O2 sensors left to right, If you now get a P0430....It's the O2 sensors.

I would bet money it's NOT the O2's


2001 Chevy Camaro L92/4L80E
2006 Chevy 2500HD LBZ/Allison 1000
2010 Toyota Corolla 2ZR-FE/Auto
Re: 2006 chrysler 3.5 300 [Re: jeep58] #4622064
01/02/18 07:30 PM
01/02/18 07:30 PM
Joined: Feb 2009
Posts: 59
ny
jeep58 Online content OP
jeep58  Online Content OP
Joined: Feb 2009
Posts: 59
ny
Thanks

Re: 2006 chrysler 3.5 300 [Re: HoosierJeeper] #4622075
01/02/18 07:37 PM
01/02/18 07:37 PM
Joined: Apr 2010
Posts: 4,398
Storrs, Connecticut
jeepman3071 Offline
jeepman3071  Offline
Joined: Apr 2010
Posts: 4,398
Storrs, Connecticut
Originally Posted By: HoosierJeeper
Only use NTK on anything Mopar! O'Reillys carries them.


Yup. Lots of guys on the Jeepforums who use Bosch or something else and have issues or poor fuel economy.


2000 Jeep Cherokee 4.0L (180k) - Pennzoil 10w30, Napa Gold 1516, Magnefine trans filter
2009 BMW 328i (33k) - Castrol Edge Euro 0w40, MANN HU816X
Re: 2006 chrysler 3.5 300 [Re: jeep58] #4622147
01/02/18 08:50 PM
01/02/18 08:50 PM
Joined: Mar 2014
Posts: 3,268
NJ
Leo99 Offline
Leo99  Offline
Joined: Mar 2014
Posts: 3,268
NJ
From what I've read, worry about the ones upstream first. They are usually the ones that go bad and are usually easier to replace. I know the downstream one on my Corolla was a real bear to get out.

Changing the O2 sensors did fix the P0429 code in my Corolla.


Without data you're just another person with an opinion. W. E. Deming

2003 Corolla 250,000 miles
2004 Rav4 359,000 miles
2015 Camry 59,000 miles

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