I have a 2001 Lincoln LS V6 and when I start it.

I have a 2001 lincoln ls v6 and when I start it it will idle high then lower down but when I go to give it gas once it hits around 40mph it spudders and wont go any higher then if I go to put it in gear the car shuts off. When you look at the exhaust its a thick white smoke and it has a very rich gasoline smell. I plugged it up to my computer and it said piston 3 and 5 are misfiring and the egr valve popped up. I put a new egr valve in the car and nothing happened so I know its one of the sensors but I replaced the one behind the motor and nothing happened and I disconnected the battery to reset the computer but nothing happened so I took the head off the motor and looked inside and there is like an inch thick of carbon build up inside the head I was wondering what sensor is in control of the carbon and if I replace that sensor it would fix the car