My check engine light came on about 2 weeks ago. I had the codes checked and the DPFE sensor was bad. I got that changed. When driving home that same day, the check engine lights comes on. I got the codes checked again and its the same thing. I want to change the actual EGR valve out. Where is the valve located and how hard is it to change? Someone said to me that it's located in the throttle body. Is that true?