My 06 ss was pushing 12 1/2 boost but now can not push past five any ideas on what is wrong or what should I do?

 

Is it throwing any codes?

Car probably went into limp mode.

 

I have never had my engine light come on my abs light did once but I shut it off and started back then it was fine when I pull up to stop lights and stop my idel goes up as if it will die but then will go back to normal after it goes up and down. But it's been doing that before I lost boost