in my grand marquis i had a vacum problem so i replaced the tp sensor the idle air control valve and the evap purge solenoid. i drove around for about 20 min and the check engine light came back on so i took it to autozone to read the code again and it said that the tp sensor was bad again. is it possible that i got a bad sensor. should i disconect the batt for a while to reset the computer.. i aslo had some other codes come up the first time i got them read.. a cylnder 8 misfire,purge or vent valve was bad, or bad tp sensor. like i said i replaced the purge solenoid and tp sensor and the misfire and purge solenoid codes were gone and the tp code came back. please help.......

 

It is always possible to get a bad sensor. Take it back to AZ ands have them replace it.