Ive had this truck for about 4 months and every 3,000 miles ive changed oil, so since then i changed the oil twice. I ran an Obd reader and I got a P0300. Which is a multiple misfire which is why I looked up the code. I already changed the spark plugs, spark plug wires, distributor cap and rotor. What would be causing my oil to be black? Smoke comes out of the exhaust but not as often and it is black as well. What would be the problem?

 

Most of the time random misfire is due to secondary ignition parts. The only thing left that you haven't changed is the coil, low fuel pressure can cause it as well. The black smoke is unburnt fuel. What brand did you replace everything with?

 

About the only thing the oil color can tell you is that it's doing its job of suspending contaminates. I suggest a used oil analysis from a place like Blackstone Labs.