Just got my HPT VCM Editor the other day and couldn't wait to play with it.
Well I ran into a problem trying to read my 98 Zs PCM. Sent an e-mail to HPT's customer service with all the info they requested when a customer encounters a problem. Keith from HPT got back to me right away. He checked out the logs I sent him and he sent me back an updated file. Clicked on the file in the e-mail and up popped the HPT's install shield and downloaded the new file. Piece of cake, and mind you I'm not the most computer literate person out there.
I was finally able to delete the DTC codes that have plauged my car ever since I go it tuned. EGR, O2s, MISFIRES, etc. These have kept my car in limp home mode for the last 5 months, and let me tell you IT SUCKED. Copied/pasted the high octane table to the low octane table because I still have a bad KNOCK sensor. Disabled the knock sensors while I was at it. I know this isn't the best way to do this, but I have the wonderful 3.96* KR mod so I needed to see what would happen. I'm getting 1-2* of KR now, but it goes to bellow 1* as the revs climb so I suspect it's the Pacesetter Y-pipe banging on take off. If it was real knock it would increase as the revs went up.
I adjusted shift points (on 98s you have to do it by MPH and not RPM from what I've discovered. Someone please correct me if I'm wrong, I'm a newbie at this.) Disabled the TCC in 3rd gear for better throttle response in 3rd. Raised tranny line pressure and the tranny shifts clean at approx 6250 rpm or so. More testing at a later date with higher shift points. On a side note, while looking at the bin files I read from my PCM, pre and post removal of the HPP3, I discovered that the HPP3 does indeed raise line pressure at WOT and not just at part throttle as I've read on the boards. Matter of fact the file I edited and wrote back to the PCM still contains the HPP3's tire and gear code. Works just fine this way, didn't see a reason to change it.
I haven't yet played with the engine tuning itself, need more practice and a good wideband O2 for that. In the 3-4 hours of playing with the HPT's VCM Editor I have come to the conclussion that this is a easy to use and wonderful tuning tool. Money well spent.
PS: If anyone's interested, I got a 98 deprogrammed HPP3 and EFI Live for sale. Good products if you're in the early stages of modding your LS1. Probably shouldn't be saying this seeing as I'm wanting to sell these 2 items, but for about 150 bucks more than the price of these 2 used items you can buy the HP Tuners VCM Editor and get a great tuning tool and excellent customer service. Well, E-bay here I come. LOL