This weekend my 2007 G35x with just over 100,000 miles threw two error codes at me. One was P0455 - Powertrain which appears to be something between the gas tank and gas cap that I haven't had time to locate yet, but the other is C1500 - Chassis. I haven't been able to find anything about this error code online, wondering if anyone has every seen it. Last week I was driving in rushhour traffic at about 100 degrees out and heard the sway bar bushing noise that seems to be well known, not sure if that is indicative of anything besides the bushings needing to be replaced or if it's just coincidental.