[mustang_chick85]

I just bought this mustang, I replaced the plugs and wires, replaced the right manifold and valve gasket covers.. it idles rough, the car shakes and It's awful while driving down the road. Once I hit 50mph it sounds like a freight train. I have been reading about the when valve and dpfe.(or whatever it is) sensor and I think those could possibly be the culprit. Any ideas? Thanks

 

[heavy metal]

Welcome to the site!!

 

[wmburns]

The usual symptom of excessive EGR flow is power loss and bucking at low/part throttle. IMO it's unlikely that anything directly related to EGR is causing your issues. Focus instead on the misfire or anything related to misfire.

If you are certain this is EGR related, then 1st CLEAN the EGR passageways inside the throttle body. Make sure the vacuum lines to/from the DPFE sensor are leak free. If the EGR related DTC code continues, then replace the DPFE sensor. The failure rate on the DPFE sensor is quite high. Exhaust gasses are hard on rubber/plastic parts.

Confirm that the correct spark plug routing has been followed. Double check that all factory standoffs and looms have been used.

http://www.allfordmustangs.com/foru...king-rough-idling-injectors-next.html#2951811

What are the results of a compression test?