I put a 96 integra type r in my civic and its been running fine for a while now but i took it to the drag strip last weekend and ever since its been idling weird. When the car is in neutral it will rev up and down. Somebody told me it was a sensor on the manifold so i clean but it still seems to do it. If anybody knows what might be causing this problem could you let me know. Thank

 

vacuum issue maybe, check the hybrid forums...