Hey idriveawhiteeveo! I know it's prob bad that I'm on here but I saw your post and I had to talk to you. I have a 2001 IS300 with an SAFC 2 on it as well. I think the problems I am having are very similar to yours. My car doesn't necessarily have to be at 2500 rpm but it does do it more when I'm going up hills or pushing it. I called Apexi and they told me the specs to set it at and it ran ok for a little while then started up again. If you have any information on why your car did that please feel free to email me at moxpox@hotmail.com. Any help would be great. Thanks!