Hello, I have a 1996 twin turbo manual with 64k miles. I recently started having the check engine light come on sometimes and other times it doesn't. When I checked the codes these are what I got : If anyone has had these same codes what did they change to fix the problem. Car runs fine with check engine light on but want to fix issue. Any help would be greatly appreciated. Thank you. P0400 P0136 P1150 P1155