P0420 Cat converter

Tiny
CRAIG3777
  • MEMBER
  • 2002 CHEVROLET IMPALA
  • 213,000 MILES
I have a 2002 With a P0420 cat code. The factory cat was replaced a couple of years ago after becoming clogged, and had no issues to almost a year later when a P0420 code came on. Eventually after dealing with some aftermarkets that didn't work, I replaced it with a Catco (OEM assuming?)Cat about a year ago. Once again, I have a P0420 code again. The o2 sensors are fairly new. I did have some autolite plugs installed on my last tuneup. I have recently replaced them with AC delco's and it seems to run a little better, especially when the engine is cold. Why am I burning through cats? What should I look for?

thanx
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Tuesday, November 15th, 2011 AT 3:45 PM

10 Replies

Tiny
RASMATAZ
  • MEMBER
Too much unburned fuel is being dump into the exhaust-check the CTS, O2S, thermostat and worned out engine
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Tuesday, November 15th, 2011 AT 3:51 PM
Tiny
CRAIG3777
  • MEMBER
What is a CTS?
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-1
Tuesday, November 15th, 2011 AT 3:55 PM
Tiny
CADIEMAN
  • MEMBER
If your having a performace loss. Remove the o2 and test drive to see if it runs right. This tests for a clogged exhaust.
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Tuesday, November 15th, 2011 AT 4:12 PM
Tiny
WRENCHTECH
  • EXPERT
That converter has to be still under warranty. Have them replace it.
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Tuesday, November 15th, 2011 AT 4:14 PM
Tiny
CRAIG3777
  • MEMBER
It's seems to drive ok, but the temp gauge has been erratic for a few years, Assuming a CTS is a coolant temp sensor? On warmer days it will move just past the middle position, but never overheats. How do I replace the CTS being a driveway mechanic?
I bought the cat myself and had someone install it. Too many miles, can't cover it under warranty.

Thanx!
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Tuesday, November 15th, 2011 AT 4:19 PM
Tiny
WRENCHTECH
  • EXPERT
5 year/50K
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Tuesday, November 15th, 2011 AT 5:21 PM
Tiny
CRAIG3777
  • MEMBER
LIMITED WARRANTY This catalytic converter is warranted to be free from defects in
material and workmanship subject to the exclusion and conditions set forth below and subject to the durational limits in this paragraph. This catalytic converter has been designed and manufactured and is warranted to meet federal Environmental Protection Agency emission requirements for 25,000 miles. The stainless steel body and the nipple alone are warranted for 5 years or 50,000 miles, whichever comes first. At the conclusion of the 5 years/50,000 miles on stainless steel body and nipples or 25,000 mile period, whichever is applicable, all liability under this limited warranty shall terminate
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Tuesday, November 15th, 2011 AT 5:27 PM
Tiny
WRENCHTECH
  • EXPERT
Federal law requires 5/50

Catalytic Converter Warranty

The Warranty on your New Catalytic Converter is Important to You!

Converter Warehouse provides full warranties on all catalytic converters. This warranty complies with all EPA regulations and statutes.

Following is the specific warranty that pertains to your new catalytic converter. As mandated by the United States EPA this warranty is the same for all new after market catalytic converters and their manufacturers. It is valuable to note that any replacement converter purchased from a car dealer has only a 12 month or 12,000 mile limit on the warranty. This is considerably less than aftermarket cats.

All new catalytic converters sold which meets EPA requirements must be properly labeled and warranted to comply with the Federal Durability and Performance Standards Act. New after market catalytic converters must have a 5 year / 50,000 mile warranty on the converter shell, casing and end pipes and a 25,000 mile warranty on the converter insides or substrate. It must meet all EPA's emission Performance Standards when the vehicle is properly used and maintained.
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Tuesday, November 15th, 2011 AT 5:33 PM
Tiny
CRAIG3777
  • MEMBER
It;s gone over 25k in the last year.I bought this catco Cat through ebay. So the aggravation it may cause me trying return it (too Catco?) May not be worth it. I can get another for a $150 and pay some slob to install it. The temp coolant sensor sounds like it could be the cause and should have been something replaced a long time ago, especially since it's an inexpensive part. Sooo. Is the ETS fairly easy to replace?
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Tuesday, November 15th, 2011 AT 5:39 PM
Tiny
DR. HAGERTY
  • MEMBER
If the engine is not in proper fuel control, the cat is at risk. To determine fuel control, have the exhaust gas analyzed and take those 5 gas readings to freeautomotivecalculators. Com and plug the numbers into the equation. Start there.
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Sunday, December 11th, 2011 AT 4:38 PM

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