Since the implementation of the new STAR smog check program, smog stations are being very careful in ensuring vehicles are equipped with proper/required catalytic converters. The smog check technician will check your vehicle's catalytic converter EO numbers. The EO number must be visible. If it appears scratched off to a degree where it is no longer legible, the vehicle will fail the "visual" portion of the smog inspection. If you believe that the EO number on the catalytic converter of your 2000 Toyota Tacoma is scratched but should still be able to be read you may want to have a second smog station conduct and inspection (as you have with success!!! Yes!). If they too are unable to read the numbers you have the option of getting a smog inspection from a California smog check referee office. In any case the technician must be able to read the EO number in order to determine the CAT is designed for use on your specific year, make and model vehicle. A vehicle having passed a prior inspection is not proof that its current smog components are California legal.
The following is a PDF by C.A.R.B. explaining the California CAT inspection procedure and guidelines.
www.smogtips.com/Aftermarket_CAT_ARB.pdf
As far as returning to the place you bought the CAT from and asking them to fix the EO number... making it more visible, our assumption is that they may have to file a warrant claim with the seller. Should the seller accept the claim, you'll be required to send back the old CAT and have them replace it will a new one. You'll want to check with the manufacturer on this matter. Depending on how long ago you purchased the catalytic converter, they may or may not honor your request.
