The truck is a 99 f150 4x4, 5.4. The error code that I keep getting is 09o1 (EGR Flow insufficient), we have replaced the EGR valve, replaced the DPFE sensor and replaced the hoses to the DPFE sensor. However, after all of this the truck continues to have a bad miss and the check engine light comes on occassionally. Anyone have any idea what this could be or what I need to try next.

Thanks,
Coty

 

When you replaced the valve, did you check to make sure the EGR passage was clear?