intake or head gasket?

my 2000 impala, 3.4 with 166000 miles on it has started blowing coolant out of the exhaust and threw up a p0302 misfire #2 cylinder code. The #2 plug is completely coated with fuel/coolant, the #4and 6 plugs look good other than burning real ritch (expected due to #2 problem). I am leaning towards the Intake gaskets need to be replaced but part of me also suspects that maybe it is the head gasket. The car has been parked for 2 weeks and I have coolant leaking from the seams of the muffler. Any ideas?

Because of Age + Mileage, I would have no problem trying some www.steelseal.com (http://www.steelseal.com)

I suspect a head gasket.
I just did my 00 impala 3.4L head gaskets. (225,000 miles)

You can test if you have a few things.
Air compressor, compression tester.
Take the hose from your compression tester, Remove the check valve with a tweezers. (it should unscrew)

Not screw the compression tester hose into the spark plug hole for the cylinder that is in question. Now attach the hose from your air compressor to the compression tester fitting you dont need alot. Like 40 PSI, no higher then 90 or you'll have a hard time turning the engine. Grab a socket wrench and start turning the engine by hand. You should hear a few things.

If you hear Air pouring out the throttle body/intake, keep turning, You may hear hear air pour out the exhaust manifolds, keep turning. Once both valves closed your cylinder will compress. IF suddenly you hear a whoosh of coolant and bubbles start coming into the coolant reservoir. Then you have a blown head gasket.

But with you saying that you already have coolant out the muffler. That almost confirms it. A leaky intake gasket, will pour coolant into the oil. Head gasket will pour coolant into the cylinders.

I haven't tried the "Steelseal" but it looks like snake oil to me...
If you are mechanically inclined, you can do this job. It will take awhile because there is so much to get.

What will you need?
Head gasket set. (upper end set)
Head bolts
intake bolts.
Torque wrench
Sockets, wrenches, and swivel.
New Dexcool antifreeze.
Oil, filter and Motorflush by GUNK
A local machine shop, incase you break any bolts. Plus you'll want to check your heads for straightness.
After 225,000 miles I didn't need to resurface my heads.

Here's a few pictures of my impala head job.
http://gallery.computervitals.com/main.php?cmd=album&var1=Impala/

Upper and lower intake gasket leaks are very common on the 3.8, change them both. There is a new design gasket out (Felpro I think) that works much better than the GM one.

I agree with others that it is the intake gasket. I replaced that on mine with the FelPro and it solved the problem. Also, because of all the junk being blown through your system you will likely need to replace the catalytic converter as it will take that coolant and become blocked up and you'll be wondering why you have no power on acceleration.

Best wishes on your fix.

3.4 liter is prone to head gasket failure. Its more common to see them fail in the minivan/suv's but they do go bad across the board.