rexxar

I bought a used 2000 Malibu in January, and while it's been a pretty reliable car (MUCH better than my Dodge Stratus that caught fire out of nowhere), she's needed a lot of TLC. All of the vacuum hoses and other rubber fittings are basically dust, so I've replaced everything I can find. I started to replace the fuel pressure regulator today, and I found some new hoses with issues.

First off, the PCV hose doesn't seal very well into the intake plenum, and there appears to be a small amount of oil around it--should I be concerned about it? I replaced the valve and grommet a month or two ago.

There's another rigid hose that plugs into the top of the air intake and runs to the back of the engine. On the engine end, it's got a rubber seal that's cracked and crumbling. What is this hose for, and should I replace it?

FWIW, the only check engine code I have is for a bad IAT connector, but I'm getting pretty bad mileage, around 13MPG. I'm hoping the pressure regulator is the reason for it, we'll see what happens after my roadtrip this week, hopefully I'll get closer to 23.

While I'm here, are there any common issues with this car that I should check out? I know about the ignition switch recall (though I still haven't gotten around to scheduling a fix). All in all, I'm pretty impressed with how well it's stood up to 200K+ miles, I'm reasonably confident it'll last another hundred or two to get me through college.