I just got a hypertech power tech chip and what I was wondering is why you have to use the stock chip with it dosent the hypertech chip use its own program or does it use something form the stock chip It was just something i was wondering thanks

You still need the limp home chips and in some applications the esc module is on the old chip. You are using the Hypertech program from your new chip for regular operation, but you still have the limp home chips in case of a failure.