I've had my 98 z28 for 2 years now, it's programmed, and it has the cat's cleaned out. It has always ran perfect. Recently, the engine started to knock. The mechanic i went to told me he thinks it is the knock sensor, that it may not necessarily be bad, but may just need to be reset. Also, he said it could be that I have the cat's cleaned out. Is there a way to use the hypertech programmer to reset the soft code, and has anyone else had this same problem?