I have only one check engine code, P402 - "Exhaust Gas Recirculation Flow Excessive Detected". The EGR valve was carboned up but appeared to be working properly. I removed it, cleaned it out with carb cleaner, replaced it, and the trouble when away. Two weeks later and the same error is back. The engine performance seems fine. Any other parts that could be bad such as a DPFE sensor?
Thanks! Mark