I had built a 350 vortec engine LT-4 Hot Cam and 454TBI. I received a chip last November of last year from TBIchips.com. I just started the motor July 4th and it ran rich. I contacted Brian (TBIchips.com) and explain the situation and how I will be going on deployment this Saturday. Short n sweet, I mailed the chip back Monday and got another chip today (Friday). Tried it out and the car ran alot better better. Due to last minute prep for tomorrows deployment, I am unable drive the Camaro with its new engine. Again thumbs up for TBIchips.com