Any chance this bolt is lock tighted in? Can I apply a heat gun to this area or will I damage the plastic intake and plastic MAP sensor?

 

I think I would try and avoid the heat gun.... or, be VERY careful with it......

 

So there is the head of the bolt getting stuck, as well as the threads. The vibration will eventually loosen the rust on its own, chems tend to speed it up a bit. I will every so often test to see if I can just get it to move, just a little. Then douse with chems and move it back and forth until its ready to come out. Don't just go crazy trying to get it spinning out right off. Just take your time, and apply patience... else you'll find yourself getting to understand how to use left hand drill bits and screw extractors - definitely not much fun.

 

Well I finally got it. I went out and bought a brass punch and spent 1/2 a day on the light tapping / penetrating oil routine.
My horizontal dremel cut was getting a little worn for my screwdriver so I decided to hand cut a vertical slot using a hacksaw blade.
I then grinded down a screwdriver blade to fit the hacksaw slot. I used the largest screwdriver I could to get the most leverage.
I then removed the AC condenser to give me more of a head on shot at the bolt.
That thing was so tight but eventually it snapped free. Thanks for all the great advice.

 

Congrats, rust is a b*tch. If you haven't already been incentivized to invest, I bet you're ready to now add anti-seize to every fastener you're going to install..

 

I love that stuff. Won't turn a wrench without it.

 

Remove the AC compressor to give you more room. Blast it with liquid wrench, wd-40 or PB-Blaster and let it soak, then try to get it loose.