How to change thermostat on a 2005 kia sedona

Question edited for clarity.
Question moved to sub category.

P0304 is only a misfire error to cylinder 4.

https://www.700r4transmissionhq.com/p0304-kia-sedona/

There isn't a 'fuel control module'.

https://www.google.com/search?q=2005+Kia+Sedona+2EX+3.5+Fuel+control+module

But there is a fuel pressure regulator

https://www.google.com/search?q=2005+kia+sedona+fuel+pressure+regulator+location

When you look up fuel 'module', you come back to the fuel pump.

https://www.google.com/search?q=2005+kia+sedona+fuel+module+location

One thing you might try is moving coil pack 4 to another cylinder and see if the code moves. After that do a plug swap and see if it moves. Do them separately not coil and plug together..
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The thermostat on the early Kia Sedona with the 3.5-liter engine is located toward the passenger's side of the engine, near the front. On all models, follow the lower radiator hose from the radiator to the engine. The lower hose enters a semi-dome shaped housing that is attached to the engine by three bolts. This is the thermostat housing, and the thermostat is inside.

How to Remove It

Drain the coolant from the radiator to minimize coolant spills. Remove the three nuts from the bolts that secure the thermostat housing. Remove the housing and pull out the old thermostat. Carefully note the thermostat orientation so the new one can be installed in the same orientation.
Credit https://itstillruns.com/location-housing-2005-kia-sedona-7578743.html

are you referring to the drain plug? if so, it is located on the passenger side bottom facing the front bumper. see attached diagram under radiator removal.
http://www.kia-forums.com/attachments/kia-carnival-sedona/9678d1319024147-removing-radiator-kia-sedona-2005-remove-radiator.jpg

Hello, cdavis1402 and thank you for asking your question on Fixya!

Here is a simple process that will walk you through a few steps that will pinpoint the overheating problem on your 2005 Kia Sedona, without even using any tools. It has helped millions of people, and I am certain that it will help you, because I wrote it for people in your exact situation.
How to diagnose your overheating 2005 Kia Sedona

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Thanks for the vote, and good luck!

How to diagnose an overheating KIA

is the thermostat in backwards ?

YOU COULD HAVE A BLOWN HEAD GASKET, MOST REPAIR SHOPS CAN DO A BLOCK TEST WHICH WILL TELL YOU IF HEAD GASKET IS BAD, ALSO CHECK TAIL PIPE FOR WHITE COLOR SMOKE.

Location of components...

Here is a link:
http://wiki.answers.com/Q/Where_is_the_thermostat_and_how_do_you_change_it_on_a_2003_Kia_Sedona