About a month ago I bought a 1995 Subaru Impreza Outback with the 1.8L engine and a manual transmission. I have about a 10 minute commute every morning on back roads, and as I was driving in this morning, my check engine light went on, flickered a bit, and went off. It did this several times. The flickering was not a regular flickering, and it was quite slow. On for a second, off for half a second, on for two seconds, off for a second, etc. Each time it lasted no more than 10 seconds. I turned off my radio to try to listen to any odd engine noises. I didn't hear anything loud, but I did notice a higher-pitched sound that I haven't noticed before. It wasn't a squeaking, but it seemed like it was possibly connected with the engine, because pushing the clutch in or out didn't make any kind of difference. Every time the CEL would flicker on or off, there was an electric clicking noise, but I'd assume it has to do with the light itself, and not the problem.

The car is still under warranty, and I intend to take it to the dealer, but my schedule is really tight until the weekend. (Today is thursday). This afternoon I'm going to go check the oil and the gas cap. Would it be advisable to disconnect and reconnect a battery terminal? I saw that suggested here several times.

Some other things about the car:
For the past week the car has been idling kind of low (around 500-600 rpms).
The day the car started idling low, I noticed a coolant puddle on the ground. The engine didn't overheat, and I found a cracked hose, took it to the dealership, and they replaced it free of charge.
Yesterday a friend of mine's battery died, so I attempted to jump it, but my car's battery terminals are kind of corroded, and I was unable to jump him. I think the previous owner (I am the second owner) had kept it outside.

Any help is greatly appreciated.
Thanks a bunch.

Everything on the car is stock.

 

UPDATE:

I checked all of my fluids, tightened the gas cap, didn't touch the battery. All of my fluids are fine, I took the long way home to give it half an hour running to see if anything happened, and there was no check engine light.

 

Today the car didn't want to start. It started after cranking for about 8 seconds.

 

You can use a mixture of baking soda and water to wash off your battery terminal. It will take the corrosion right off chemically.

Get the CEL pulled at an autozone or kragen or wherever, most places do it for free. Then we can help you better figure out what's wrong.

 

Autozone et al. can't read codes on a '95, it's OBDI and they can only read codes on '96 and newer OBDII cars.
For info on how to read codes on older Subarus, check here-
http://www.troublecodes.net/Subaru/
I think however, from your description of the problem and how the light is coming on, that you may not have codes being set but rather an overall electrical problem. Your corroded battery terminals may be the cause of all this, take them off and clean off all the corrosion from the battery posts and the terminals themselves. Make sure that all contact surfaces on the posts and inside the terminals are clean and shiny. If the terminals and/or cable ends are in really bad shape replace them.
Check the battery for leaking or overflowing electrolyte which can cause the corrosion, also check the alternator to be sure it isn't overcharging which will cause the battery to overflow.

 

Thanks a bunch. I took it in to the dealership and it turns out its a bad coolant temperature sensor. I'm going to clean my battery terminals (carefully) once I get the car back.

Thanks!