I have this intake on my car, so I may be able to help you.
1) This intake supposedly needs no tune. However, for some people, it threw codes after it was installed. I was one of the lucky ones who never received any codes. Every car is different. You should have it tuned to prevent the computer from throwing codes and to get the best gains from the intake.
2) You can take the intake off and reflash the car back to stock. If the dealership notices that it the computer has been reset, you can just tell them that you disconnected the battery. When you get the car back, you simply reload the tune.
3) It will not hurt your gas mileage enough to notice. I can't recall if I gained or lost mileage, but it has been over a year since I've had mine installed.
Hope that helps.
1) This intake supposedly needs no tune. However, for some people, it threw codes after it was installed. I was one of the lucky ones who never received any codes. Every car is different. You should have it tuned to prevent the computer from throwing codes and to get the best gains from the intake.
2) You can take the intake off and reflash the car back to stock. If the dealership notices that it the computer has been reset, you can just tell them that you disconnected the battery. When you get the car back, you simply reload the tune.
3) It will not hurt your gas mileage enough to notice. I can't recall if I gained or lost mileage, but it has been over a year since I've had mine installed.
Hope that helps.