Like Triple's was saying . . . can you find a friend and some impact tools? I would definitely give that a go before I put everything back together.

Side Note: Triple's has like 10K posts and this is the first time I've seen his name.

The tool for removing locking lug nuts without a key might work. It bites into the rounded bolt head to get a strong grip.
Other options are to reassemble and let a muffler shop finish the job or if all else fails, you could remove the header and cat together to allow easy access to the rounded bolt.
Sorry to hear you're having this problem. I just installed hfc's last night by myself with no problems. For those that haven't done this install yet, the importance of having a quality six point socket sitting squarely on the bolt head before applying torque can't be overstated.
Also,don't use impact wrenches near your wideband O2 sensors.

Kevtex makes a great point. Before you ever start to apply force to a bolt like this it is very important to ensure you have the socket placed fully on the bolt.

You could try one of these, and go at it from the top of the engine bay with some long extensions taped together
http://base0.googlehosted.com/base_m...9eb5c377&hl=en

Whatever you do, don't try this guys approach So, Dont buy a VW - Honda-Tech

yeah after looking at it, you need to be VERY careful on the driver's side bolt that is next to the steering shaft. Even with the knuckle, the shaft makes it EXTREMELY difficult to get the socket sitting on the bolt head fully. I guess my troubles started when my first 6 pt socket cracked up the side. It popped so loud we thought we got it. The only getting was the pain me and my brother got in our forearm and elbow from slamming into the enginebay ;0 <ouch>. I'm going to take it to a local shop that has done a couple 370 CAT jobs. We will see...

I got a set of these from AutoZone and the first time I used it, it stripped the inside of the "cutting nut" out. :eek: and just spun after that.

A skilled user of the blue tip wrench will get the job done.

The would have to be VERY skilled... I dont see how you are going to get a cutting torch down there.

i had this same issue except on the passenger side in which case i i used a dremmel to cut half the bolt where it meets the header and i was able to break it loose because the pressure was relieved. using this tool thats pictured above will not work its just going to strip and spin, Ive tried it. you basically just screwed yourself as there is no room on the drivers side to get a dremmel down their. only way is to drill it somehow.

There are flexible extensions for drills. Maybe something like that could help you out. You would still need an extra man below with gloves on to guide and keep aligned the bit.

Hey CBRich,
I'm always in the Prem Section, I do come out on Ocassions but rarely post unless a Troll Appears then I'm in the thread with a bat.... :tiphat

Well, I got brave and stuck the propane torch to it. Me and my brother got it cherry red and it still would not budge. We put the car back together tonight. I'm taking it to the local shop tomorrow. <crosses fingers>

This morning in the shower (calm down Frost, I know what you are thinking), I had a brain storm. If this local mechanic can't remove the bolt, what if I JB welded the socket onto the bolt; let it set up and then tried to remove it?

So go ahead and do it before you take it to the mechanic. I would hate to see anybody here defeated by a bolt.

JB weld is not a good idea, as it is not strong enough.