I had been hearing a light metallic rattle from under the right idle of my car at cold start. I got a chance to look under the car today found the second O2 sensor plug on my Toda header loose. I didn't want to use locktite on the plug, So checking will just be part of changing oil. I think the early Toda headers only had 1 O2 bung, Where as the later ones had 2. I just thought I would give a heads up to the Toda owners.