Hello my name is Steve, I recently bought a 1996 sc400 it was running fine till now. I did a quick search and didn't find much info about this issue. The codes were P0300 P0304 P0306 P0307.
Car starts fun but idle is kind of rough(misfire).Please let me know where to start looking.Thanks

 

P0300 is "Random/Multiple cylinder misfire detected"
The number at the end is which cylinder, aka p0304 is cylinder 4, p0306 is cylinder 6 etc..

The easiest/most common issue is the plugs and plug wires. Check that your wires are all plugged in tight and in the right order, if they are and it still happens I would go ahead and replace the wires and plugs. If that doesn't fix it, check your distributor cap in case its loose or cracked.

Let us know if that doesn't fix it.