I need some knowledgeable SERIOUS HELP

Hello to all,I recently rebuilt my 96 2.4 l engine and had the code P0401 turn up.After countless hours of research and following the online advice,the code is still there. I removed the EGR valve and cleaned it,tested it(applied vacuum to it,truck stalled),so its good.Next I checked all the vacuum hoses and connections,all good! I took the top intake off and removed the EGR valve and found that port clogged almost completely with carbon!After 6 cans of carb cleaner and alot of work,the clog is no more!The only thing left is the vacuum modulator or the vcv valve!On the internet all the talk is about the vsv valve.On my truck,that valve (vsv) is connected to the charcoal canister,which has nothing to do with EGR according to the mechanics Ive talked to.There isnt anything online as to the vaccum control valve which is connected to the manifold and vacuum modulator.My question is which is the likely culprit to the code?The vcv or modulator?Any advice would greatly help my sanity! Ive got only days left for my truck to pass smog!

 

I had a persistent P0401 on mine. Cleaned the valve, replaced the modulator, and still had the problem (code would pop up after about a week of driving). I finally removed and cleaned the EGR temp sensor (on the intake manifold near the EGR stuff.) Now the code pops up every 8 months or go. Good enough for me. Those sensors are real pricey.

 

I will give that a shot Thanks!Any other advice anyone?