EGR problem

I had a P0400 light come on. I replaced the EGR valve twice now, i dont remember if it was related but i've also replace the idle air control motor. This has been an ongoing issue for like 2 years now that i periodically try to fix again. Anyways, there is a tube that goes from the vacuum control valve to the throttle body. If i take that tube off the throttle body, my car idles pretty normally. When i attach it back, my car spudders and eventually dies. I thought for sure since the other parts didn't fix it, and this thing goes to the vacuum control valve that replacing it would solve everything. Well, it came in the mail about 30 minutes ago, i replaced it...and still have the exact same problems. Has anyone had this issue and fixed it or have new ideas on how i can get this darn thing fixed? I thought about just leaving it alone since it drives and runs fine with that tube off, but i occasionally get white smoke coming from my exhaust with it that way. I can post pictures of whatever would be helpful with ideas lol


Its a 2000 DE 2.4L

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I doubt it is helpful information, but i just remembered that i had a light for the IAC which is why i replaced it. As soon as i fixed that i got the EGR light. I've also replaced the EGR Solenoid already

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Explanation of the code to save some people time...

P0400 is an OBD-II generic code that the engine control module (ECM) detected the engine exhaust gas recirculation (EGR) valve is not flowing recirculated exhaust gases when it is commanded to open the flow of gases into the intake manifold.

Did you check if it's the PCV valve? Also check if disconnecting the Mass Air Flow sensor allows the car to run smooth.

The PCV valve seems fine, since its pretty cheap ill just replace it to be safe. And last time i checked, disconnecting the MAF made the car die, but i'll check it again