Hello everyone! I just bought a 93 civic ex that already has a greddy catback exhaust, hedman header, Zex racing camshaft, aem cai, and a coolant bypass mod. My question is, sometimes after driving, my car idles at about 800 rpm, and then jumps to about 1200 rpm. It continues to do this constantly at idle. What could be causing this? Is it the coolant bypass mod? Also, the engine is noisy under acceleration, but isn't when in neutral and I'm revving it. Is this the camshaft causing this noise? Thanks for any help everyone!