The Check Engine Light may illuminate due to an evaporative emission (EVAP) system fault. Our technicians tell us these EVAP system faults can be difficult to diagnose but it is not uncommon to find a failed charcoal canister or a loose or worn gas cap.Google+
Car Problem Reports
Toyota Corolla Check Engine Light Due to EVAP System
Toyota Corolla Problem
Average Mileage: 118,500 mi (41,000 mi - 174,000 mi)
Visitor, 1998 Toyota Corolla, 41,000 mi
It came on for a week or two, had it checked via computer, said "low flow, both sides". I cleaned the gas cap rubber gasket and applied light coating of oil. This fixed the problem, but only temporarily. I'll eventually take it in for service, because there's an EPA settlement w/Toyota that provides an extended warranty on the evaporation system, from the gas cap up to the manifold: 14 years or 150,000 miles. Google it if you're not sure. And print out the documentation to show the dealer, because some of them aren't aware of it.
My check engine light came on this morning and I went and got a diagnostic test they said 2 things came up both pertaining to evap. So now after reading all of this not sure what to do?