I have a 95 Z28 It came with some kind of tune.the previous owner put in, I want. to put in one of my own but i heard if you don't pull the old one out it will lock up. i don't think it will but i just want to make sure. also how do i get the tune out i don't have the obd tuner box. thank you in advance for your help. Mike

 

1994 and 1995 are flash based. You don't have to pull the chip. You can tune with an ALDL cable (look up ALDLcable) or the new ALDL bluetooth adapters (not the OBD2 bluetooth adapters; look up red devil river or 1320 electronics). You will need some software for your laptop, probably tunerpro or tunercat. It automatically overwrites the old tune; I've never heard that you need to remove the old tune to not lock up the ECM. You probably do want to download the current tune to use as a baseline. Alternatively, you may find someone who has the stock tune file that you can use as a baseline. You can lock up the ECM or 'brick' it if you interrupt the upload process. This is where the laptop is sending the new tune to the ECM. If you mess with anything (mayble your laptop goes to sleep) you can trash your ECM. I think that is the only risk. Good luck!