I drove it again today and all of a sudden while idling at a red light the noise intermittently stopped?! I let it idle for an extended period of time in the driveway and the noise would subside occasionally, then come back. To me it almost seems like something is loose and rattling. I seriously doubt its any of the exterior accessories because I removed everything and made sure to tighten everything when I put it back together, but are there any parts within the intake/throttle assembly that could possible come loose and cause an obnoxious rattle? Any other internal parts that could come loose? To me now it seems like it probably isn't a major moving part of the engine since it seems to come and go at random. But I could definitely be wrong on that. Thanks for the help,

Dan