Thanks Deathrat. I know, its a pcu/pcm not a chip. Does it plug into the OBDII port BTW?

Yes it does.
It'* a plug-n-play device that allows you to revert back to stock parameters once unplugged....great if you need gm service work!

I'm a little confused. Does my '95 SSE Series II have an ECU or PCM? I was told that '96 and up use PCMs and before that it was ECUs. What'* the determining factor? Is it the year or the engine type? How can I tell for sure? Is it indicated somewhere on the VIN number? I'd rather get the PCM controller than having to replace the ECU.

An easy to determine is too look at your engine cover.....If it says "Series II" then you'll need a PCM controller, if not then you'll need a "Chip" instead.

I've just updated this item'* description thanks to a customer of mine that was so kind to provide it for me so others may know before hand what to expect if they get this item & want to install it themselves.
JET PCU

Do both need premium fuel by chance? I saw the Hypertech one does but what about the Jet one?

I probably would have to say yes (based upon the Hypertech Unit). :?

This is a tempting upgrade but if gas prices go high this summer as people are saying I don't think I will want to be putting 91/93 octane into the car

I've just purchased this used. It was easy to install but you need to do one thing different if installing in an 00+ Bonneville. PM me if you would like additional information.

Fuel grade does not matter.

Speaking of gas prices, the cool thing about the PCM is that you can unplug it to go back to normal settings.