I have a 03 silverado 5.3. I'm having seen fuel pressure problems. I just installed a new aem 320lph fuel pump and filter and still only about 30psi of fuel pressure. I've changed the regulator as well. Last night when I was driving home the check engine light came on. I got home and scanned it and the codes were P0131,P0200,P0174,P0151. I'm at a loss. Any one got any ideas?

 

Maybe a dented/bent fuel line? Have you checked the ground resistance on the fuel pump?

 

I've checked the fuel lines and I didn't see any dents in the line. I have not checked the ground resistance at the pump. Maybe a newbie question but how would I do that?