Years ago I swapped a B-18a1 (1991) into a Honda Civic DX (4dr) with a pr4 computer at obd0. Well, it's been fun with B-18a1 but now my motor is spitting smoke at 2500rpm without hesitation. My question: Can a 1994 B-18b replace the 1991 B-18a with the same pr4 computer? The catch is that I have a CA Ref Tag. I would still want to be legal with the exchange from 1991 B-18a to 1994 B-18b. Is this possible? Does anybody have any information or know where information is for the type of motor exchange I have explained above. Thanks ahead of time for any help.