2004 Jeep Liberty code PO304

I need three things checked and in this order,

1) Remove the #4 plug and ground it to check for spark to that plug. If you have spark, go to #2

2) Check for an injector pulse to the #4 fuel injector. If there is a pulse, go to #3

3) Complete a compression test on cylinder 4 to confirm there is adequit compression.

Do this and let me know what you find.

That will cause it. The first thing you need to do is a visual inspection of the wiring to that injector. Make sure it is not damaged or shorting. Also, check all connections to make sure the pins are not pushed out of place and they are not corroded. Let me know what you find.