P0401 error code 2001 Isuzu Rodeo 2.2l

Question

I have a 2001 Isuzu Rodeo with the 2.2l engine. I am getting error code P0401 and I have replaced the EGR wit a new one. Am still getting the code. I have tried to clean any possible plug up below the EGR by putting Sea Foam down the EGR throat while engine is running and put a air hose down their to try and push any loose stuff out. I have also removed the throttle body and soak and cleaned it good in gumout overnight. In addition I cleaned the fuel injectors with Seam Foam. I can get the check engine light to go off for a few minutes but only to come back on. My guess is the ECM may not be talking to the EGR or there is faulty wire between ECM and EGR. Could the O2 sensor be faulty in causing the EGR to not work properly without tripping the O2 fault code ? Am at my wits end on this. Any ideas appreciated.

Answer 1

P0401 Exhaust gas recirculation insuffieicnt flow detected

When the EGR open the PCM uses the MAP (manifold air pressure) sensor change in its  input as the EGR opens,when the MAP goes out of limits then it codes up P0401,It does not use the 02 sensor,