Hello Guys
Really could use some help with the tune on my brother's nightmare of a Hummer H2. Hummer sat at our local chevy dealer for about a year and a half after it broke down on my brother while driving. Chevy changed out body control module, ECU, Interior lighting and hacked up a major part of the harness under the dash. Had my brother pick it up and bring it over to my shop and started checking compression leak down test and fuel pressure readings. I tracked the issue down to cracked heads. We ended up rebuilding the full motor and installed a stage 3 BTR supercharger cam kit with dual spring kit and trunnion kit. we also had to bore the block .030 over. Installed new factory heads which should have been upgraded but wasn't my money to make those choices. Hummer had a Kenne bell side mounted supercharger and a course the chevy dealer reprogrammed the old ecu before installing the new one. So, we towed this thing to 2 different tuners around town and this thing is running horrible. second tuner left it worst then the first. So decided to try it myself if not just planning on ordering a remote tune. But hoping to learn how to do it myself and been trying to do as much research as possible. So if I could get any help, it would be greatly appreciated.
2003 Hummer H2
LQ4 bored .030 over
BTR stage 3 cam
Kenne bell supercharger 3lb pulley
3200 stall torque converter
kooks headers with high flow cats