Ok guys I have an 05 honda civic ex with manual trans. When I bought it the D17a2 had a blown head gasket, so instead of fixing it I bought a JDM D17A. Now it was plug and play for the most part, did have to use the USDM throttle body to still have cruise control. Here are my questions that I cant seem to find any answers to. 1) do I need the JDM ECU, I was told the usdm ecu would be fine. But my car seems to get bad mpg on the high way but great in the city. 2) Now ive read that the d17a2 has e-Vtec that kick in around 2500rpms. Is the jdm version have the same e vtec. Seems like it never kicks in. I do have a AEM ram air and a axel back if that makes a difference. Any help would be nice, seems like this is a rather unusual choice for a swap resulting in very little information.