We get asked by prospective buyers fairly often whether ECMLink will simply drop into their car and run like stock. It sounds like an easy question, but it's absolutely not. There are SOOOO many variables involved that we have no way to guarantee anything related specifically to your car.
Ideally, and in most cases, the answer is yes. If you order ECMLink configured for your injectors and MAF (airflow sensor) setup and there are no unusual issues with the car to begin with, then yes, ECMLink should drop in and run like stock.
If it does not, then you have to figure out what, specifically, about your car is not in alignment with the assumptions. And that can be a serious can of worms. You may still have a GM MAF translator device installed and configured for your aftermarket injectors, for example. Or your fuel pressure may not be holding as steady as you assumed it was. Or you may have a big boost leak somewhere. Or your ignition wires may be failing, etc., etc.
We really try our best to help users sort out most common issues with their cars, but that seems to be getting harder and harder as cars get more and more out of whack. Please keep in mind that issues with your car are not our responsibility to fix. We do try our best to help, but ultimately, if there's really a problem with your car, that needs to be addressed first. If there's a problem with our chip and/or software, we'll jump on it and get that resolved. But if you're having problems getting your specific car dialed in, there's only so much we can do from this side of the keyboard.
To get started, I would highly recommend reading through the Quickie A/F Setup page. And I mean read through it…don't just skim it and assume you know the basics. I mean read through it and really understand exactly what's being adjusted and why and how. Understanding the basic concepts of fuel trim and airflow readings will really form the foundation of everything else.
If that page seems a little much to absorb at first, then start with our ECMLink 101 page.
You can also watch the demo videos on our website. These really seem to help orient people quickly on how to get started.