I have been trying to clear a PO401 Code EGR system. I have replaced EGR vacuum modulator valve +EGR valve + MAP sensor. I havd no reason to believe the PCM is bad. This is a 4 cyl engine. I expect to check vsv next, but am convinced this is not the issue either.
After talking to experienced mechanics, I am led to seek something deeper in to the engine. For example, the EGR Large Port Intake - it is suggested - feeds a stream to 4 smaller inlets/ports - one for each cyl - these are not visible or simple to get to and these smaller ports most likely have carbon buildup which is constricting the flow, I am told. I accept this notion and would be ever so thankful if you could tell me where these are on my engine - and how to get to them. Any links to exploded, labeled diagrams would be very instructive. I do have the Haynes Manual for the model.
Thank you again for your help,
have the same problem?
Thursday, October 20th, 2011 AT 1:59 AM