A Toyota dealer will be able to look up your vehicle's emission specs from the "public" VIN which is located both on the driver's side door jam and behind the windshield on the lower left hand side (driver's side). You may also use the California Air Resources Catalytic Converter lookup to find the aftermarket EO number
of the catalytic converter designed for your 2004 Toyota Corolla. Just a nore...The emission label is not required to pass a smog check. Also, you may be able to order a new emission sticker from Toyota.