5rebel9

Unfortunely you should probably go right back in there and make sure the plugs are torqued properly.
Did you use a torque wrench to install them? I have seen the platinum tip fall off a new plug after a few days before; but it caused a cyclinder misfire code only. The tiny point was fired out the exhaust valve and never damaged any thing.
 
A loose plug however will rattle and rapidly damage threads. You don’t want to have to install a heli coil to fix a damaged thread after driving a week. My 2 cents, free advice worth everything you pay for it.

@cbeja    I know you must be pretty "frazzled" with life and fighting a vehicle problem. But please respond with how things worked out and what was the problem and fix....for the benefit of the many fellow Journey owners here.   

Like the above post's story...Check the engine oil level for overfull reading(coolant in the crankcase). IF OK then refill the res.and see if it drains away or leaks out somewhere. Take off the top motor "dress up" cover to look for leaks on top of the motor. Yes when overheated air doe get entrapped in the cooling system, let it set with cap off for at least 1/2 hr and recheck the res. level  and top off accordingly. You STILL need to find out WHY it overheated and fix that, as I posted of the many possibilities of parts/components that can cause overheating.   Good Luck!

First thing to offer is some other places to check for possibly where the coolant went to find a possible cause of the overheating.
Check the engine oil, both on the dipstick AND on the fill cap. You are looking for brown "milkshake" residues and high (overfull) dipstick reading. Next look inside the coolant reservoir and see if there is red oil in it. These will determine if a major problem in the engine or transmission has happened.
 
You didn't state mileage of the vehicle, and so there are a number of reasons overheating can happen, from minor to major expenses, like a bad rad. cap or thermostat to engine oil cooler failure to blown head gasket or bad radiator. If you are not a DIY'er, Have it TOWED(by FLAT BED due to being an AWD vehicle) to a reputable repair shop for a good diagnosis  and proceed from there.    Good Luck.
   
 

It's been a month since this thread was started with NO response back from the OP. Stated NO code,NO turnover, NO sound. From his picture of the gear position, would lead me to think bad battery or cable connections(ground or positive). I've seen this a few times with Dodge family minivans.

Thanks for bringing this video here! yes the Journey is one of the easiest to change...as long as the glove box is not crammed full of stuff! One can spend more time emptying and replacing "junk" that doing the task itself.   

It's been a month since this thread was started with NO response back from the OP. Stated NO code,NO turnover, NO sound. From his picture of the gear position, would lead me to think bad battery or cable connections(ground or positive). I've seen this a few times with Dodge family minivans.

Last posting was 1 year ago and not by the OP.  One offering I can suggest as a newer member here is to check and make sure the gearshift is fully in park. Next step would be to get at the battery and make sure the cables to it are not loose. I've seen a number of times that "new" batteries posts are smaller in size than OE and don't let the terminal ends fully clamp on them. All it take is some kind of "jarring" and they will break connection, killing all power to the vehicle.

@cbeja    I know you must be pretty "frazzled" with life and fighting a vehicle problem. But please respond with how things worked out and what was the problem and fix....for the benefit of the many fellow Journey owners here.   

First thing to offer is some other places to check for possibly where the coolant went to find a possible cause of the overheating.
Check the engine oil, both on the dipstick AND on the fill cap. You are looking for brown "milkshake" residues and high (overfull) dipstick reading. Next look inside the coolant reservoir and see if there is red oil in it. These will determine if a major problem in the engine or transmission has happened.
 
You didn't state mileage of the vehicle, and so there are a number of reasons overheating can happen, from minor to major expenses, like a bad rad. cap or thermostat to engine oil cooler failure to blown head gasket or bad radiator. If you are not a DIY'er, Have it TOWED(by FLAT BED due to being an AWD vehicle) to a reputable repair shop for a good diagnosis  and proceed from there.    Good Luck.
   
 

First thing to offer is some other places to check for possibly where the coolant went to find a possible cause of the overheating.
Check the engine oil, both on the dipstick AND on the fill cap. You are looking for brown "milkshake" residues and high (overfull) dipstick reading. Next look inside the coolant reservoir and see if there is red oil in it. These will determine if a major problem in the engine or transmission has happened.
 
You didn't state mileage of the vehicle, and so there are a number of reasons overheating can happen, from minor to major expenses, like a bad rad. cap or thermostat to engine oil cooler failure to blown head gasket or bad radiator. If you are not a DIY'er, Have it TOWED(by FLAT BED due to being an AWD vehicle) to a reputable repair shop for a good diagnosis  and proceed from there.    Good Luck.
   
 

So, NO CEL after the plugs but "idling rough"? If a bad coil you should still be getting a flashing or steady CEL when driving.  I'd more believe a sticky fuel injector at those conditions. Try a can of SeaFoam fuel system cleaner in the gas tank, run it thru and see how it may change for the better as the cleaner works thru. NOTE...this is not an instant fix result. BUT if you are getting CEL again, get the codes read and posted here, many possibilities and without codes responses are GUESSING.

So, NO CEL after the plugs but "idling rough"? If a bad coil you should still be getting a flashing or steady CEL when driving.  I'd more believe a sticky fuel injector at those conditions. Try a can of SeaFoam fuel system cleaner in the gas tank, run it thru and see how it may change for the better as the cleaner works thru. NOTE...this is not an instant fix result. BUT if you are getting CEL again, get the codes read and posted here, many possibilities and without codes responses are GUESSING.

So, NO CEL after the plugs but "idling rough"? If a bad coil you should still be getting a flashing or steady CEL when driving.  I'd more believe a sticky fuel injector at those conditions. Try a can of SeaFoam fuel system cleaner in the gas tank, run it thru and see how it may change for the better as the cleaner works thru. NOTE...this is not an instant fix result. BUT if you are getting CEL again, get the codes read and posted here, many possibilities and without codes responses are GUESSING.

It's your ride and your call on how to proceed. A lot of disassembly of timing components to lift the heads off and HOPE you don't end up with a bad head. Good Luck! 

Oh, I didn't take it as a complaint or anything negative. Good to know that that info doesn't actually show to everyone though, so thanks for that.

Try a new radiator cap ! 
    Yes, ot sounds like there have been some "issues" out of the normal seen "quirks" these motors have. Of all the things said done, there's been no mention of the cap and it is a known "quirk" with ALL 3.6 motored FCA model vehicles.
   As for no heat in front dash vents, yes blend door  actuator OR a plugged heater core.... Also air entrapment in the cooling system can cause similar problems. Try a new cap and make sure to properly bleed air from the cooling system before "running down the road" with the car.

And my point of posting was lets find out WHY you feel the cats MAY be plugging up and fix that cause, BEFORE having to shell out that kind of money for parts that will go bad again if the cause is not found and fixed. 
  Busting loose the catalyst substrate in the converters by "banging on them" will plug the exhaust piping and cause even more backpressure of exhaust gases back into the engine , thus definitely making the vehicle want to stall.

It would be very help[ful for members to try and assist you if the actual code number were posted. There are diagnostic steps to be taken for any code that appears to pinpoint the actual fault of what has set that code. If members don't know what that code or codes are, then any offerings will be nothing more than guessing.
  Also, an 09 with how many miles and what maint.(like spark plugs) has been done beyond the posted EGR valve. Yes the EGR is a rather finicky system on all FCA vehicles with the 3.5 motor, and a hanging open EGR can cause stalling out at idle when in gear.

It would be very help[ful for members to try and assist you if the actual code number were posted. There are diagnostic steps to be taken for any code that appears to pinpoint the actual fault of what has set that code. If members don't know what that code or codes are, then any offerings will be nothing more than guessing.
  Also, an 09 with how many miles and what maint.(like spark plugs) has been done beyond the posted EGR valve. Yes the EGR is a rather finicky system on all FCA vehicles with the 3.5 motor, and a hanging open EGR can cause stalling out at idle when in gear.

Years ago?...whole diff technology now. Cats only "plug up" from 2 main causes. Overly rich running engine(poor mileage and operation and usually CEL) or excessive oil consumption(burns oil, not leaking out).

I'm almost certain that only the 2.4 motor employs 2 thermostats. BUT all engine options are notorious for air entrapment that will cause problems if not "bled" properly out before "taking off" and driving the vehicle. 

I'm almost certain that only the 2.4 motor employs 2 thermostats. BUT all engine options are notorious for air entrapment that will cause problems if not "bled" properly out before "taking off" and driving the vehicle. 

YES, well aware of the "age factor", having just recently gotten the vehicle and not speaking with the past owner (in Maryland) to know when the issue started leaves the question of just what caused the "failure". As the sensor does NOT go entirely dead, just goes from low reading to extremely high numbers and everywhere in between when driving the car. Who knows, there may have even been "fix a flat" used in the tire/wheel at some point that affected that sensor....tires look like new and why I posted as such previously.
    My friend is very busy right now and I'll have to wait a bit till he has the time to to the task. I still rue the day that I sold off my tire changer and balancer!!

With the low oil weight used in these motors today that is pretty common to see, and I wouldn't be worried about any engine problem from that. Yes you can change the filter, but also check for a small filter inside the air box where the equalization hose is. that needs replacement also from time to time. They used to be foam and later years went to a paper filter. On these really new cars today, they may have eliminated it altogether to save money.
    Enjoy your DJ!