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. If they don't match the required CAT EO numbers for your vehicle will fail the visual portion of the smog check as an "emissions tamper". This is probably what happened in your Honda Accord's case.
We should mention that Section 24007 (b)(2) of the Vehicle Code states it is the responsibility of the seller to provide a valid smog certificate at the time of delivery of the vehicle. There is no provision in the law to sell a vehicle "as is", as it relates to the smog check.
The buyer has the option of paying for any repairs necessary to get the car to pass the Smog Check but may end up taking the seller to Small Claims Court to recover their costs. Although the law clearly supports the buyer, collecting on a small claims judgment can be difficult, so the amicable solution is usually best.
You may want to contact the seller and see if they will help you remedy this situation. You'll need to have the correct catalytic converter installed on your Honda Accord in order to pass the smog check and get the vehicle title transfer completed.
