well my car feels good pulls good for an hf and after like 10 or so min of driven it starts running bad and dosnt pull well what could the problem be im throwing a code 12 witch is the egr but could this cause it?

 

Well was it throwing that code before it ran crappy?
Its always good to fix all codes first, then go from there.

 

yes it runs crapp all the time but only throws the code ever once in a wile