p 0339 and p 0300 diagnostic codes ( multiple cylinder misfire and crankshaft position sensor intermittent ) wondering if anyone else has any info/experiance with them.

 

I seriously doubt this is your problem but I had a brand new JK with 124 miles on it throw this code. I had it towed to the dealership to have the sensor changed and here's where it gets interesting!

They changed the sensor and the Jeep still wouldn't start so they started taking things apart. It turns out an EXTRA bolt was left between the torque converter and the transmission and that bolt got slammed around inside ultimately putting a hole in the transmission housing. Needless to say I didn't take that Jeep back. They gave me a new one