Hit a snag during 3100 LIM gasket replacement-rear valve cover bolt?

[Oklahoma]

It's been a while since I posted on here--I'm home for spring break finally getting around to taking care of everyone's cars and I now seek the advice of 3100-lower-intake-manifold-gasket-replacement veterans... Last year my sister got a 1996 Grand Prix with a 3100. It has 177,000 miles on it now and last Thursday I got the oil report on it back saying that there was coolant in the oil. I suspected this knowing that the LIM gaskets were a very common 3100 issue and the car's approaching 200k miles (although it runs perfectly fine). I got the manifold off and the pushrods out, but I did this without completely removing the rear valve cover--it's held in by 4 bolts but I couldn't get the rear driver's side bolt out. The problem is, the valve cover itself obstructs access to the bolt head from the above/front direction. And then, there's this stud (that nothing attaches to) that comes up out of the head and obstructs access to the bolt from the rear. Does anyone remember how they got around this? I can get a socket on the bolt (8mm) but the stud gets in the way of any wrench or extension I would try to put on it. I have tried with no success to unscrew the stud. I only tried the 8mm box wrench on one side of the bolt, now that I've removed the ignition coil I can try to use it on that side too--and I would if my 8mm box wasn't currently lost within the depths of the Grand Prix's engine bay... I will probably try to borrow one. Well anyways, that's my story, if anyone has removed the rear valve cover on a 3100 before you may know what I'm doing wrong and I would be glad to hear what it is.

[86euro]

That stud is there so the coil pack mounting bracket has something to mount to. So you can't use a 1/4 drive short 8mm socket with a short extension? This will be at a slight angle so it will require a little bit of pressure to hold the socket onto the valve cover bolt. Using a 1/4 inch ratchet with a flex head is very helpful here. If the bolt is stuck tight or slightly rounded, the stud will likely need to be removed. IIRC, a 4mm socket fits on the end of the stud.

[Zaloryan]

When I first pulled the cylinder heads on the 3100 on my 1996 Ciera, the previous owner had rounded off the very bolt you are talking about. I ended up having to literally break off the valve cover and install one off a donor car...I'm able to get clearance to that bolt with a 1/4" ratchet and an 8mm socket. As far as the stud you're talking about, it threads into the cylinder head and is one of the studs that mounts the ignition coil packs & evaporative emission solenoid. IIRC, you can loosen that stud via hand and it will thread right out.

[Oklahoma]

Ha, after I got the stud off I still couldn't get the bolt out--it had been ruined. I don't think it was the previous owner's fault in my case though--my dumb ass chewed that bolt up! So I thought about breaking the valve cover and hitting Pull-a-Part for a new one but decided that I could work around the issue... in other words, I was able to loosen the rocker arms with a combination wrench with the valve cover on, and then I reused the old gasket because it looked good and didn't use sealant. I developed a trick for using the torque wrench and combo wrench together to get the rocker arm bolts to the right torque when I put the pushrods back in.
I put the car back together and it was running well at first, then after a few miles of driving started to run rough and threw me 4 CEL codes. The lower radiator hose was leaking as was a coolant hose near the throttle body but I got those tightened up Friday.
Now I'm going home again this weekend so I can finish the car--that is, fix whatever's causing the CEL to come on which will, in turn, presumably fix the roughness in the engine (which is mostly at idle, and I think also mostly when hot). Now for the check engine codes: I got one for EGR, one for TPS, and 2 for MAP. So for the MAP, do I need to start looking for a vacuum leak at the manifold? I feel like it could be around the injectors. I have a bad streak with fuel rail installation... My best trick for finding leaks is spraying water where I think they are and looking for bubbles, so I guess I'll try that. As for the EGR and TPS codes, I don't have any idea why they're there. They weren't there before.
I don't have any more information since I'm not with with the car... I will be back under the hood Friday night though.
In the meantime, my 16-year-old sister gets to drive my Ciera for a week... not her idea of a 'cool' car to be seen in but she does like driving it.
Any advice? I think all this school and living in Atlanta is already turning me into a crap mechanic...

[Prospeeder]

if they wernt there before, check connectors and vacuum hoses.