Hey everyone , so today I floored my Wj but after about 2 seconds the rpm gauge acted like it slipped from the transmission and just went up to about 5,000 rpms and the engine light came on along with a bad misfiring of the engine. It sounded terrible. When I got home thinking the worst ,I checked the codes and got P0304 and shut off the engine . Well to my surprise when I restarted it the misfiring was gone completely and run perfect again. What could cause this?
Thanks!

 

Low fuel pressure. That code is for a misfire on cylinder #4.

 

Could you please explain more on the low fuel pressure ? Im not too experienced and would like to hear more about why this would cause this problem.
Thanks!

 

If the fuel pressure is not up to spec the engine will be starved for fuel at high RPM and cause a misfire. Have you checked the transmission fluid lately? Low fluid could be the cause of the slipping feeling you felt.