Chip should not be stock with 36 lb injectors. Pull the ECM cover and see what sticker is on the chip. It may give you some clue as to who's it is. 160 stat will not hurt anything except the ability for the car to go into closed loop idle, your chip may be burned to run in open loop at idle anyway. Change the stat you should not have any problems, except passing the emission test depending on where you live.