Help!!! Engine light on...again!

[Jrinkenb]

Malfunction light came on Friday the 14th, on my 05 Jeep Liberty Sport, not running any different. Took it in and got the code checked on Saturday, just to be safe, and got the #3 misfire detected (PO303?). Cleared the code off, is there anything I can check to see what caused the light to come on? I already checked the fuel cap, and all the caps under the hood.
What would have caused the light to come on and what do I check to fix it?

Light came on again last night, jeep was running in park for about 10 minutes and it came on again. Engine sounds as though its running a little louder than it should.
What should I check? Jeep only has 49,000 miles on it.

 

[Treyz02KJ]

when was the last tune up? (spark plugs, filter, wires) it cant hurt to just add a can of injector cleaner to the next tank and do the plugs if its been like 5k or more since the last one. i had this problem on the #5, and ended up causing other problems, i think it was long term driving with a misfire that led to the replacement of the first engine.

Not to scare you at all. these motors actually are quite strong in my opinion. you see these guys on here with these huge tires and just needing to change the gears. These motors are good, just have a couple of design flaws (IMO).

 

[Jrinkenb]

I just had the jeep serviced 2 weeks ago. It was completely checked over i June before I bought it.

 

[jeepkj02]

Try moving the coil pack from cylinder 5 to another cylinder and clear the code. If the misfire code moves to another cylinder then you need a new coil pack.

Wouldn't hurt to check the plugs either and do a seafoam treatment to clean the engine and fuel injection system.