1991 Toyota Previa is there an adapter for the obd2 check engine light computer to attach to the computer of this vehicle
not that I know of. you read obd1 codes using a paper clip or jumper wire in the obd port. I think it is terminal te1 and e one, but I would consult a Haynes manual, or just google it. it is a simple procedure and involves counting check engine light flashes. there are youtube vids on it all over the place.
Search Toyota Previa Questions
Are you a UK consumer? CarGurus now has a discussion forum in the UK.
Toyota Previa Experts