Build date? If it was made anywhere from about Sept on it's actually a '96 model. Could also be a Cali spec truck.. they got everything a year before the rest of us. I know you are in Canada but you are on the left coast apparently and trucks do move back and forth across the border.

 

I belive its a late 95. was made in Canada . I shall get a pic soon as i can .I still have the stock exhaust too, but wonder if my cat is near its life .
Also previous owner put a car muffler on it . sounds all quiet and nice but not a truck sound as it should be . So I plan to stay with same size pipe, but change out muffler and have the cat go missing .
280,000kms, and still no oil burn

 

OBD-II would have an O2 sensor after the cat so you would have to get trick the computer to thing the converter is still there. I would replace it with a high flow converter and call it good.