I just installed a reman 4.7 into my 06 Dakota. It ran great before the engine blew no codes ever. After installing the reman from a reputable company, I now am getting the PO300 code. The engine runs great, doesn't seem to stumble but I am getting this code. I replaced all sensors on the engine but none on the manifold when I installed the new engine. All Mopar parts except the EGR valve. I have switched some of my old sensors back onto the engine to see if I got a defective part. I took the truck to the dealership to reflash the Pcm and have them try to figure out the issue. I have done all of the proper tests except a leak down and compression test. Supposedly those happened before the engine left the rebuilder. I'm stumped. I'm at my wits end with this issue and I can no longer just throw money at it. Anybody on here have any ideas that I may have missed. The scanner data is all in compliance with factory specs. My truck is bone stock. The spark plugs do look like it is running lean but it holds 22" vacuum at idle warm. Thank you in advance to all who throw some ideas my way.
