Grasping at straws as nothing turned up helpful searching Google. Two issues. Oil leak and Check Engine light. Hoping there are people among us who know more than a little about car engines.

History, then recent chain of recent events.

History:

Last Christmas I blew the engine in my 1997 Subaru Legacy Outback. Put in a used engine. Not rebuilt, used. All belts, valve cover gasket, rear main seal, etc, were replaced at that time. The replacement engine leaked oil from the oil pan. Very minor oil loss. Took it to my main mechanic, then back to the guy in West Virginia (where I was when the old engine blew) on my mechanic's advice, since it had a 6 month warranty.    Was told by the guy who installed the used engine the leak was essentially unfixable and to just be sure I checked my oil weekly. (I am just now figuring out I may have got snookered on that one.)   The guy said this model Suby didn't have a replaceable oil pan gasket.    I have religiously checked the oil. It is hard to read the dip stick. I am assuming it is my failure and difficulty reading the dip stick, but it seems like the oil level as indicated on the dip stick fluctuates somewhat irratically. I have had the experience, more than once, of checking the oil and the reading indicating I am more than 1 quart low. Add a quart, and then check it again, and the oil level is over the full line. Or I might check it one morning and it is halfway between the full and fill lines, check it the next morning, and it is at the full line. I usually check the oil in the morning after the car has been sitting all night.   I am pretty sure that more than once I over-filled the oil. Now I'm leaking oil from the rear main seal and the valve cover gasket. Leaks are still minor in terms of loss of oil.

Immediate problem and recent chain of events:

Friday I had the car inspected. It passed the emissions test with no problem. It is hard to find information about the North Carolina emissions test, but they apparently hook a computer up to the engine to check the emissions control system, i.e. they do not stick something in the tailpipe to read the exhaust emissions. Drove some but not much after that. Less than 40 miles Friday evening and Saturday. Went out late this afternoon. Weather has been cold and wet since last night. It sounded rough and weak when I started it. Drove one block. There was a definite miss and the engine light came on and started flashing. Also what sounded like a belt squeal. Stopped immediately. It smoothed out just a bit, so I limped the block back home to the driveway - engine light intermittently flashed and stayed solid.

Turned it off, popped the hood and restarted it a few times. The squeal had disappeared.    At first it was still missing badly.    Came inside and started googling. Flashing check engine light=stop driving immediately.   Solid check engine light, you can drive it, but get it checked out sooner rather than later. Went back out and started it again. Miss was gone, seemed to have full power and to be running smoothly. Check Engine light is on and solid.

My mechanic is about 12 miles from here. In the morning, f it starts and runs without noticeable miss and the check engine light is solid, I will drive it there rather than have it towed.

I'm wondering (hoping) if it is possible the inspection guys didn't connect something back solidly after they did the emissions inspection, that whatever they plugged back in perhaps rattled loose and is the source of the problem?

I am assuming the oil leaks will not do further damage to the engine as long as I don't allow the oil to get too low. They are going to be an expensive fix and if I can hold off for 2-3 months I'd like to do so.

Hope this post isn't too incoherent. I live 40 miles from where I work and both are rural locations. Haven't sussed out a mechanic in the little town where I work now. Don't have a mechanic in the little town to which I moved. The mechanic I have been going to for about 10 years in the little town where I did live is honest but not inspired. He has done no work on the Subaru, which I bought soon after I moved, and I have only been to quick oil change places since I moved, except for the engine replacement that occurred 300 miles from home.