Download pdf  https://drive.google.com/open?id=0B4-Q_2x5fHnDYnoxSlY4ak5nYkU

Hi make sure the coolant temp senor and the air temp senor are very close to the same
reading when cold starting check your pids should be within 5 degrees of each other
replace incorrect senor also make sure the engine reaches operating temp

Hold a steady speed of 55mph (88km/hr) for five minutes. During this time, in addition to the diagnostics performed in step 4, the catalyst monitor diagnostics will be performed. If the catalyst is marginal or the battery has been disconnected, it may take 5 complete driving cycles to determine the state of the catalyst. Check this site: http://www.obdii.com/drivecycle.html