Hey, so I recently brought an LS430 with a cylinder 2 misfire. So far I have switched ignition coil 2 and 4, cleared codes and reran, code reappeared for cylinder 2. Then I changed out spark plug 2 for a new one, cleared codes and reran. Then the same code for cylinder 2 misfire came back. I'm a bit lost with what to do next so if anyone could help that would be amazing. It has a bad battery that keeps discharging, im not sure if that could possibly lead to an issue like this. Also to make sure im not being really dumb, when you look at the car from the engine bay, cylinder 2 is the left one closest to you correct?

 

Any oil present on the plug end of the coil?
Replace the battery first and foremost.

 

100% agree replace the battery these cars do wonky stuff when the battery and alternator are dying.

 

No oil on the plugs and yeah Ive got a battery coming in soon.

 

How quickly did cylinder 2 misfire code come back? What code did you get? It could be a wiring issue to the number 2 coil. With motor idling try disconnecting the number 2 coil pack connector and see if the idle changes, plug back in see if it changes, see if you get a different code.

It could also be a fuel injector. Hopefully it's not a mechanical issue like a burnt valve. Try taking a look at your long and short term fuel trims for both banks, but primarily bank 2. Could give a clue.

 

I'd say the car started recognizing the misfire around 5 minutes into a drive, i could recognize it while idling almost immediately. The warmer the engine the more prominent it was, so the lower the revs were the more I could feel the misfire. The code is P0302 Cylinder 2 misfire detected

 

Read up on the fuel pressure dampers as I think I read that they can cause this also. There are 2 and are easy to see and get to and threads in this forum.