valve cover gaskets; exhaust bolt trouble

My engine’s been running rather poorly for a while now. I have trouble pulling out into the road in front of other cars and going up hills. A valve seems to be ‘missing’ in high power (or sometimes all) situations. The problem seems to be caused by oil leaking into a spark plug hole and messing with the firing. I recently replaced the valve cover gasket and the gaskets that seal between the valve cover and the spark plug holes. Unfortunately, this made it worse for a while. I put some sealant around all possible areas of leakage, save for around the valve cover gasket, as this is supposed to be free of sealant, and would be unrelated to the problem anyway. I still seem to be having some oil leaking up there though. There is oil leaking all over the engine block as well. I’m a little worried and put off by this.

My most urgent problem is an exhaust leak. I’ve had it since I replaced the exhaust (replacing the previous, more significant leak), as I hadn’t replaced a bolt I semi-broke. It connects a pipe to the manifold. I can’t tighten it down since it’s a bit broke, so exhaust is able to leak out easily. I can definately smell exhaust while driving, which is of course bad for the health. Regular car part stores don’t seem to have the exact part I’m replacing. I plan to just get a nut of the same size, but Lowe’s and Home Depot don’t have a good metric selection. I’ll have to try a place with more. I wan’t to get that taken care of quite soon though.

While driving to try to get replacement parts, I used my brother’s car. He has a little early ninety’s Civic with mileage around 40k (an amazing buy). My that car has some power. My car’s quite anemic right now, but even in good shape it wasn’t that powerful. And I’ll bet it get’s near the mileage I get. It handles better than my car as well, which is to be expected because of its shortness. The transmission is quite interesting, with extremely short movement between gears. Only a 4 speed, but it seems to manage quite well with them; it makes it quite easy to drive. The brakes are not very good though, requiring a lot of depression before they kick in at all. They don’t feel to have much power. The steering is rack-n-peanut, so it can be hard to steer at times. I’m not sure whether I like that or not. It is a bit more reliable and easy to maintain than power-steering, but it can take quite a bit of force at times.