I have a 97 Dodge Dakota with a 5.2L and have a problem with it since I have had it. When I got this truck it smoked a lot so I was told to change the plenum gasket, so I did but it still smoked. I found out the heads were cracked and put brand new heads and gaskets, a new 02 sensor and new oil sending unit. Well my truck still smokes , I think more than it did before. My #4 spark plug is full of oil, what do you think can possibly be the problem?