Great product and very helpful tech support
I was a bit nervous after reading the instructions and warnings about making sure that all devices that use power from the car battery are turned off and/or fuses for them are pulled so I called the Hypertech tech support guys to make sure I wouldn't screw up. The instructions were very clear and the programmer worked perfectly. I was able to turn off the AFM system so my Tahoe no longer goes into V4 mode. I get better gas mileage & more horse power.