I stole this from anoter forum
just thought i wanna share it with other members
http://www.epa.gov/compliance/resources/cases/civil/caa/toyota.html
I had engine check light come on for my 98 Toyota corolla which when taken to the dealer diagnosed as a problem with canister and an estimate of about 600$. I searched the internet and found the below website, as per which the Evaporative emission control system (pretty much from fuel cap to intake manifold) was covered for 96, 97 & some 98 toyotas on an extended warranty of 14 years or 150,000 miles. This is due to a court settlement between EPA & Toyota for a manufacturing defect.
Upon taking this information to the dealer and a phone call to Toyota toll free number, my car was fixed for free.
My understanding from several online forums is that for Toyotas, a typical reason for check engine light is this canister problem.
Below is the link where more details are available.