Would empty coolant resevoir cause check engine light to come on?

Low coolant shouldn't light the Check Engine light but it is something that must be checked out, now.

You say there is coolant in the radiator, but is it filled to the top like it should be.

The cooling system is a closed system and coolant shouldn't disappear, so if your coolant is low, which the empty reservoir would suggest, you have a leak somewhere in the system.

Coolant Engine Light

The check engine light is a way of telling you that your fuel mixture is going off kilter. It istelling you to get some work done before expensive things start to go bad for you. It is warning you that your converter may be overheating or that your O2 sensors are getting clogged up with carbon and the engine cannot manage the fuel correcly anymore. >>>>>>>>>>>ANSWER<<<<<<<<<<Take $20 to th elocal quickky lube, and have them clean your Idle AIr Control valve and throttle body to SHOWROOM FLOOR clean. The IAC fine tunes the air/fuel mix, and is the NUMBER ONE cause of fuel metering going off track. Your enigne REQUIRES full synthetic engine oil, and NOT wax based junk cheap oil changes that makes harmful clogging vapors. SO many peopl ethink that oil is just oil, but this is s total FALSEHOOD! There are oils out there with the word SUBARU printed right on them , meaning that the oil was tested for use in SUBARU and PASSED their specifications! Mobil One0W-30 is a great choice, as are Amsoil, and Pennzoil ULTRA! These things KEEP your engine clean inside and prevent seal and gasket wear. >>>>>>>ALSO<<<<<<<<<Once your IAC is cleaned up, install a fresh set of either DENSO iridium or Twin Tip plugs, or BOSCH iridium plugs. THese will burn MORE fuel, more completely, and will ALSO keep carbon fformation down to a minimal amount. You gain up to 20% more power and econom y by doing so. GOOD LUCK< and E-mail me back with yor results!! I keep track of this stuff! rgmuske@yahoo.com