# Check engine light

**URL:** <https://community.cartalk.com/t/check-engine-light/68349>\
**Category:** Maintenance/Repairs\
**Tags:** prizm, chevrolet\
**Created:** [October 1, 2011, 8:45pm UTC](https://community.cartalk.com/t/check-engine-light/68349 "2011-10-01T20:45:31Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![system](https://global.discourse-cdn.com/cartalk/original/3X/1/d/1d47c66a543aa6c5a7873bb2320858f978ff52ed.png) [@system](https://community.cartalk.com/u/system)\
**Post date:** [October 1, 2011, 8:45pm UTC](https://community.cartalk.com/t/check-engine-light/68349/1 "2011-10-01T20:45:31Z")

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I have a 2001 Chevrolet Prizm with check engine light showing PO420 and PO446 codes, what could be the problem?

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<div class="post-metadata">

**Author:** ![cigroller](https://avatars.discourse-cdn.com/v4/letter/c/c68b51/32.png) [@cigroller](https://community.cartalk.com/u/cigroller)\
**Post date:** [October 1, 2011, 8:53pm UTC](https://community.cartalk.com/t/check-engine-light/68349/2 "2011-10-01T20:53:38Z")

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You’re probably just going to need a mechanic at the very least for diagnostic purposes. Here are some helpful web pages:  
[http://www.obd-codes.com/p0420](http://www.obd-codes.com/p0420) (possible catalytic converter failure, but could be several other things)  
[http://www.obd-codes.com/p0446](http://www.obd-codes.com/p0446) (probably vent valve or valve wiring problem)