Borrow a code reader from any major auto-parts chain, usually they'll let you borrow one for free. Find out WHY you have a check engine light, then reset with the code reader. Driving with a light on can cause damage to your engine. Until you know WHY you have a check engine light, you don't want it to go away.
Isn't a 2007 Yaris still under factory warranty? The Yaris has a 5 year/60,000 mile powertrain warranty. Take it to the dealership and make them fix it for free.
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