Most of these pre-programmed chips gain horsepower by raising your redline to dangerous levels, and changing the balance of things to sacrifice fuel economy (and definitely reliability) for power. It is possible to safely gain horsepower using a chip, by getting a chip that re-tunes your ECU to use higher octane gasoline only. I'm not sure of chips out there with this readily available, so if you really wanted to chip your ECU for performance (which I wouldn't suggest on a stock Civic anyway), the best route would be to get a blank chip and have someone tune it for you. Overall, it would probably be expensive and yield you maybe 10 horsepower maximum.