After installed TBS, I didn't feel that much gain at all. I was hoping to get more responsive from the car. Also, I saw Check Gas Cap warning massage came on the next day. After I did some research from 8th gen civic site, I found out that throttle body spacer gasket might be too loose. That was the reason why TBS performed so poorly. I tighten all bolts a little more and the car seem to response much better. But about 10-15 minutes later, the Check Gas Cap warning massage still came back. After another research, I found out that throttle body has very narrow passageway for vapor to flow from inside the car. (It's part of EVAP system). If the passageway seal off, we will get error massage from iMid. This is the solution from old style P2R TBS. They made their own passageway by shave off the TBS. In the new version, it no longer has gasket ring channel. To solve the problem, we have to modify the new gasket. I made 1-2mm. thin passageway. After install TBS and modified gasket back, the Check Gas Cap warning massage is now gone permanently. My 0-60 mph timing improve by 0.5 sec faster. This is what TBS can do at optimum performance. Update: After plastic gasket settle down for few days, tighten throttle body bolts again to maintain optimum performance. Throttle Body Spacer works best with Aftermarket intake. There is no performance gain if installed with OEM airbox intake.