# Ethanol & "Check Engine" light

**URL:** <https://community.cartalk.com/t/ethanol-check-engine-light/7600>\
**Category:** Maintenance/Repairs\
**Tags:** engines, lights\
**Created:** [November 24, 2007, 5:47pm UTC](https://community.cartalk.com/t/ethanol-check-engine-light/7600 "2007-11-24T17:47:58Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Ed\_Murphy](https://avatars.discourse-cdn.com/v4/letter/e/ea666f/32.png) [@Ed\_Murphy](https://community.cartalk.com/u/Ed_Murphy)\
**Post date:** [November 24, 2007, 5:47pm UTC](https://community.cartalk.com/t/ethanol-check-engine-light/7600/1 "2007-11-24T17:47:58Z")

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Has any research been done to determine if the recent addition of 10% Ethanol to gas has caused problems with car’s computers,specifically the Emission Control System Codes?

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**Author:** ![edb1961](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/edb1961/32/122_2.png) [@edb1961](https://community.cartalk.com/u/edb1961)\
**Post date:** [November 24, 2007, 8:21pm UTC](https://community.cartalk.com/t/ethanol-check-engine-light/7600/2 "2007-11-24T20:21:48Z")

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Gas in New Jersey has been 10% Ethanol for at least 2 or 3 years. Other than a dip in mpg, my 93 Caprice, 2000 Blazer, and 2006 have not had any problem with E10.

Ed B.

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**Author:** ![Joseph\_E\_Meehan](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/joseph_e_meehan/32/21_2.png) [@Joseph\_E\_Meehan](https://community.cartalk.com/u/Joseph_E_Meehan)\
**Post date:** [November 24, 2007, 9:12pm UTC](https://community.cartalk.com/t/ethanol-check-engine-light/7600/3 "2007-11-24T21:12:44Z")

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I don’t think 10% is going to cause any problems with any car. Are you getting a CEL? That CEL (check engine light) is just a kid in class waving her hand trying to get you attention because she has the answer. If you have a CEL you need to have the codes read. Some places will read them for FREE. Try Autozone or Advanced Auto Parts. Get the exact code (like P0123) not just their translation into English and post it back here.

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**Author:** ![mcparadise](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/mcparadise/32/32_2.png) [@mcparadise](https://community.cartalk.com/u/mcparadise)\
**Post date:** [November 24, 2007, 10:48pm UTC](https://community.cartalk.com/t/ethanol-check-engine-light/7600/4 "2007-11-24T22:48:22Z")

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E10 is compatible with just about any car, although it reduces fuel mileage. Every time I fill up with E10 my mileage drops by 10%. The check engine light should not come on just because you use gasoline with 10% ethanol.