Bad spark plugs or plug wires will cause a miss. A vacuum leak, burnt valve, or blown head gasket will also cause a miss. Replace the plugs and wires. The spark plug gap on both engines is .035. Some spark plugs have non-adjustable gaps.
The engine needs good battery power, fuel and spark to start and run. You are missing one of those.
In the engine.
spark plug loacation on 2006 jeep wrangler sport 4.0 liter engine
Can you drive it? Yes, you can but it is going to make allot of noise with that plug missing. The engine will also be very low on power, miss terribly, and you risk destroying the O2 sensors and the catalytic converter. I highly recommend you not drive this car with a spark plug missing or not firing unless you are only going a few miles to a repair shop.
.035"
.035
All spark plug gaps are adjustable.
Change your spark plugs. Check for compression. Check for a seized piston.
spark plug setting should be .044
A swivel spark plug socket will let you get to #1.
A Jeep Wrangler has one spark plug per cylinder.
.035 in GAP