# 97 chevrolet lumina ls 3.1 v6 P0420

**URL:** <https://community.cartalk.com/t/97-chevrolet-lumina-ls-3-1-v6-p0420/10268>\
**Category:** Maintenance/Repairs\
**Tags:** chevrolet, lumina\
**Created:** [February 5, 2008, 3:13pm UTC](https://community.cartalk.com/t/97-chevrolet-lumina-ls-3-1-v6-p0420/10268 "2008-02-05T15:13:28Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![gregmollet](https://avatars.discourse-cdn.com/v4/letter/g/ac91a4/32.png) [@gregmollet](https://community.cartalk.com/u/gregmollet)\
**Post date:** [February 5, 2008, 3:13pm UTC](https://community.cartalk.com/t/97-chevrolet-lumina-ls-3-1-v6-p0420/10268/1 "2008-02-05T15:13:28Z")

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i have had so many problems with this car. i just had the car tuned up with ac delco parts.before this i changed the egr valve and the intake manifold gaskets( and all related gaskets) about a day after I had the tune up done, the check engine light came on with a P0420 code. i am a financially challenged college student and this car is costing me a fortune. what is the cheapest way to troubleshoot this problem and is it going to cost me a lot to fix this? How quickly must i get this fixed?

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**Author:** ![Roadrunner](https://avatars.discourse-cdn.com/v4/letter/r/d2c977/32.png) [@Roadrunner](https://community.cartalk.com/u/Roadrunner)\
**Post date:** [February 6, 2008, 5:32am UTC](https://community.cartalk.com/t/97-chevrolet-lumina-ls-3-1-v6-p0420/10268/2 "2008-02-06T05:32:45Z")

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Code PO420 designates ‘catalyst system efficiency below threshold’.

Codes do not pinpoint trouble locations but show the area of a fault.

This one may be telling you your catalytic converter is dying.

Try to get at least 2 opinions on this as these are expensive to replace. Like I said it MAY be the fault, so get it checked out.

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**Author:** ![gregmollet](https://avatars.discourse-cdn.com/v4/letter/g/ac91a4/32.png) [@gregmollet](https://community.cartalk.com/u/gregmollet)\
**Post date:** [February 6, 2008, 4:25pm UTC](https://community.cartalk.com/t/97-chevrolet-lumina-ls-3-1-v6-p0420/10268/3 "2008-02-06T16:25:53Z")

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thank you for telling me something i already knew. if you cant answer my question please do not reply.  
my machine interprest the codes, but it give a variety of posibilities. the catalitic converter is  
just one possibility. how do i figure out what this is. NO STUPID ANSWERS PLEASE.

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**Author:** ![hellokit](https://avatars.discourse-cdn.com/v4/letter/h/6a8cbe/32.png) [@hellokit](https://community.cartalk.com/u/hellokit)\
**Post date:** [February 6, 2008, 7:21pm UTC](https://community.cartalk.com/t/97-chevrolet-lumina-ls-3-1-v6-p0420/10268/4 "2008-02-06T19:21:03Z")

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With your attitude, who wants to help you? I don’t!

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**Author:** ![Roadrunner](https://avatars.discourse-cdn.com/v4/letter/r/d2c977/32.png) [@Roadrunner](https://community.cartalk.com/u/Roadrunner)\
**Post date:** [February 7, 2008, 2:58am UTC](https://community.cartalk.com/t/97-chevrolet-lumina-ls-3-1-v6-p0420/10268/5 "2008-02-07T02:58:24Z")

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No wonder you are a challenged student.

Your name just went on the troll list.