What should I do to fix engine light, low power? on 1999 Toyota RAV4

Bought a 99 Rav4 a few weeks ago, 170,000 miles. Ran great for a while, then it quite suddenly started making a rumbling noise and having very little power- at one point it stopped outright, and while I could start the engine without difficulty, it would not move. Check engine light goes back and forth between blinking and solid. So far I've replaced the fuel filter, wondering what to do next. Getting it into a shop may be difficult, as I live a ways outside of town, in a very hilly region.

Asked by for the 1999 Toyota RAV4
have codes scanned at auto zone for free and post so we can adv
Is there a way to do so without getting the car itself to an auto zone? I very much doubt that it would make it to the nearest town, let alone the nearest auto zone. Is there a component I could remove which holds the relevant information?
You have these two choices, get a mechanic to come to you or have it towed to a mechanic.
Sorry but that is about all you can do. Good luck.
Got my uncle to read the codes himself, or what he could of them (He has a setup where he can do so with his laptop).

Diagnostics showed misfires on cylinders 1 and 4 (Though the most recent trip only showed them on cylinder 1). Also, the Bank 1, Sensor 2 02 sensor was walking back and forth between about .05 and .8.

Oh, listening to the car idling, we heard it misfire about once every 5 minutes, sometimes more frequently.
3 more answers , 2 more comments
have codes scanned
Sorry, I'm very new to cars- how would I go about doing that? And, is there a way for me to do so without getting the car itself into a mechanic? (Removing some component with the diagnostic information on it, and taking that in?)
Hey FreekyCheeseMan, I seen its been 4yrs now and no one replied back. Im having same issue. What did you do to fix it.
There were two problems. The rumbling/low power was due to a bad spark plug, which I was able to fix myself. It still occasionally lost all power, which was due to a bad ignition coil.