Thanks a lot for all the feedback. It is 2004 model; means i will need to remove both the cats !?
P.S: The mechanic, while replacing the fuel filter, broke an O-ring without realizing. Afterwards, the car was taking longer selfs to get started; but he said it is usual because of the new filter. Eventually, while i was going towards Maclod road Lahore, the car stopped. I called that mechanic, who was luckily nearby for an erand. After inspection, the culprit O-ring was replaced; again luckily, the spare part market (on the Montgommery road) was nearby. I learnt a lesson real good not to allow mechanics to get their hands on critical parts without prior thorough consultation.