I'm having the same issue. Don't really know how to use this forum thing yet but decided I'd come on to see what everyone had to say. Just like you my car goes into limp mode after it warms up and won't let me over 4000 rpm. I've replaced the oil, nox, and o2 sensors but hasn't fixed anything. Changed the oil too. I can fix anything mechanical but all of this computer stuff is over my head. Wish I could help, haha, sorry.