Well brother, there is always a little vibration in the vehicle's engine and thats normal we don feel it but thats for the reason that the frequency of the vibration is very low........
but as u have mentioned, it seems as the vibration is annoying it might be of many reasons.....due to the lack of cng tuning, which causes the air filter box to back fire where as the possibility of this is very low in civic but might be a cause......the other reason might be of the foundation tht wud be loose so u can call me any time and answer a few questions tht might not be clear to me and i might be of any help..thanks and take care
Walleed
Neat Autos, Islamabad
0303-5583065