Hey all, I am new here and I have some questions. I own a pre-owned 1997 F-150 4.6L. it had 64002 miles on it when I bought it in mid 2005. I am now up to about 130,000. Recently it started to ride rough and the engine light came on. I have a neighbor who has a code reading and it came up as a 401. I thought that my EGR valve went bad so I replaced it and the gasket. This did not fix the problem so I changed out the DPFE Sensor and this still did not fix the problem. I then tore off the Throttle Body and found that the EGR ports were completely clogged. So using a screw and some Air Intake and Throttle Body Cleaner, I proceeded to clean them out. After that, I reinstalled it with new gaskets all around, including the gasket between the two parts of the Throttle Body and the IAC gasket as well. This still did not fix the problem. I am at a loss as to what it might be at this point. Does anyone have any suggestions as to what it might be.

Other thing I have done to it recently are:

Replaced Starter
Replaced the Altenator
Replace and Regapped all the spark plugs
Replaced all plug cables
Oil Change with 0w-30

I don't think that any of these thing are causeing my problem but something is. Please Help.