check engine light with code 401 or 701. Insuffiecient egr flow. Have read cytroger and other great writeups with pics.
all I did today was disconnect air inlet hose with 4 nuts, this is under drivers seat, and sure enough the egr passageway was totally clogged with carbon as in pictures. Cleaned both with cleaner spray and pipe cleaners. Also removed the exhaust gas temp sensor with 14 open end wrench and cleaned the tip and orifice with spray and pipe cleaner. Spray would come out the now clean intake passageway and vice versa. I did not mess with the egr modulator or egr valve as these were clean in cytrogers post.
Codes now gone! No check engine light. Next time I will NOT separate the big rubber intake hose from the metal rounded intake part before pulling off the 4 wing nuts, as it is hard to put back on and not much room, but does help to take the metal intake part inside to clean it where its warm.