You may want to scratch out that pollution-under-control (PUC) sticker from your vehicle after taking a look at the results of a survey by the Central Pollution Control Board (CPCB). Most checking instruments at camps across the Capital are faulty, it states, and are prone to giving PUCs to polluting vehicles. Experts from the CPCB and the state transport department inspected 21 vehicle-checking centres (PCC) between May 25 to June 25 this year to check the operation, maintenance and calibration of instruments of the PCCs.