I have a 2001 ranger with the 3.0 v6 and 166k miles, I have a misfire in cylinder 1 and 5, I replaced the sparkplugs and wires and it still has a misfire and now the oil pressure shakes when I'm stopped at a red light. Would that mean I need to check the head gasket for cracks or leaks or are the oil and the misfires separate issues. Only codes it runs r for the misfires
Your Ranger uses a "wasted spark" type coil ignition system.
That means that each coil in your coil pack fires 2 cylinders at the same time.
It fires one cylinder on the compression stroke and another cylinder on the exhaust stroke (wasted spark).
The fact that you have misfires on 1 & 5 seems to point to the 1/5 coil in your coil pack being shorted out.
Replace your coil pack
Would you know what the problem with the oil pressure could be? It fluctuates when I'm in idle after the car has heated up. I just changed the oil and added 5qts of the correct oil and changed the filter, it is a different filter then the one that was one there but it is designed for the engine. I was planning one replacing the oil pressure sensor but I don't know if that's all that it could be. Also planning on doing a compression test based on my friends advice
You may have weak oil pump too.