CHECK ENGINE LIGHT CONTINUES TO COME ON AND SHOWS A CODE OF PO401 WHAT CAN I DO

Thanks for your response. I have used reputable mechanics from the Mitsubishi Dealership and Precision Auto Care. Mitsubishi I feel was a MONEY PIT...I spent over $400 for them to misdiagnose the problem twice. Precision has really worked hard to find the problem and have now stoped charging for their time and labor. This has been going on for months of trying to find the problem. Precision has corrected the rough idling and the car is driving fine, but the service engine light continues to come back on with the same code of PO401. That is why I am searching for answers.I need to pass the emissions test by the end of this month to get my tags!!!!

I had to ask the question as we can assume nothing here at all. sorry if I offended you. going back to the solenoid, you do need to see if it has a ground in the pcm. if the old one was shorted out, it could have taken out the pcm. pin point testing can verify the operation. you can use a test light on the ground side and see if it opens and the egr operates by the idle change. beyond that, you need a shop with a scan tool to do it through there. Roy