I was at Walmart tonight I got in my expedition went to start it and I heard a loud pop noise and then it started idling with a very loud noise I drove it home it sounded awful and smelled like gas when I got home it threw codes p0442,p1131,&p0304 nothing is leaking ive kept it very well maintenanced when it was in park it started to die and idled back up can anyone help with what's going on

 

P0304 is probably a blown spark plug ,go look at #4 coil and plug.

 

Yes I know misfire on number 4 I carry an OBD 2 scanner in my car I just can't figure out what made the pop sound and then the loud noise it's making at all times when I drive

 

Did you check the #4 and coil and sparg plug are there?

 

Yes but a coil pack and plug won't make the car sound the way it does I honestly think it my exhaust my O2 sensors r bad bc that's what code p1131 is

 

I think you are missing scrambledlife's point. He isn't suggesting a misfire, he is suggesting the plug blew out of the head and is no longer threaded in the cylinder. That would be the loud pop, followed by running terribly, being loud, and setting the other codes.

 

Yea u was exactly right my spark plug and coil pack was out of the head my husband worked on it for 3.5 hrs this morning when he got home from work and he couldn't get the plug to go back in the threads r fine until u get it almost tightened all the way so now I am still stuck without my car any suggestions

 

There are many thread replacement kits available to fix this exact issue, as it's a common issue on these engines. Time sert is a well known one, but I haven't used any of these myself so I'll leave the actual kit recommendation to someone who has done this procedure.

 

I have installed the kits that you can buy at the parts stores. It's fairly easy. My suggestion is. Put the sparkplug in the repair piece first. Then tread it in. Make sure you use the spring wire and boot in the kit. There is a specific kit for the fords.

 

I have done 3 blown spark plugs on my expedition,you have to rethread the hole for spark plug (expensive way).Once one blows the others will come and always at the wrong time.Check utube for,Ford Triton spark plug repair 4.6, 5.4 part 1,2.I used that tool and same way.