I got my Saturn in August 2012, I have had no.

It is a 4 cyl and the check engine light has been on since I got it but there is no code showing when we do the system check with the tester. Someone said it was a ghost code? Yeah, there hasnt been any issue with it up until I ran it to the light comming on and filling up at a station that I don't normally use.

Strike the "no Code" remark, there is a P0000 showing when I took it to my dads and used his obd11 tester. Now there is another issue, the radiator fan comes on within 15-20 seconds of starting the car, and runs until the engine is shut off. I removed the high fan relay and it stopped, but I now dont hear it at all. The temperature gage comes up as it normally has with no issues. Everything else has smoothed out. I think it said the P0000 code was something to do with the oxygen and the fuel? Any suggestions.

Put in 3/4 tank but already ran that out and have put 1/2 tank in twice since. There is a very very slight notice of miss or hesitation and that is only when I am driving out of the neighborhood as it is only 20 mph. At the higher speeds, I don't notice it and the acceleration is smooth from there on. The code is driving me nuts, as you said, it seems like a "dummy" code of some kind. The guy down the block said his sisters saturn had the code also and the dealer told her it was something to do with the oxygen and gas mixture not being right? I do still have the black carbon deposits from the tailpipe upon starting but nothing after the initial start. The fan however, is worrying me, I took the high an relay out an it stopped running, however, it doesn't seem to come on at all. But the temperature gage still reads as normal, coming up to operating temperature as usual. I wonder if I just leave the relay out, will it cause a problem as long as it doesn't overheat?

Not sure, I didn't know there were 2 fans as I hadnt looked under there that well evidentally. I will have to check on that and get back to you. Like I said, there was no issue what so ever untill I ran the gas low, (light came on), then put gas in from a station I don't normally use, all grads of things happened then, bad hucklebucking, carbon deposits, and sucky power. I changed the plugs, changed the fuel filter, and changed the air filter as it was totally fiflthy(salesman said all maintenance was done when the got it. Bs). The changes I did, cleared up most all of the problems but I recall now thinking about it, the fan was steadily coming on more frequently over the past 3-4 weeks untill the past 5 days or so it comes on after starting and stays on. My brother is bringing his tester over tomorrow and im going to see what that says. I really can't afford to put 1-2,000 into this thing as I just paid 2400 for it in august. I trust your knowledge and hope my information makes some assemblance of sense to you. I apologise if not, being a woman, I try as much as I can to work on my own vehicles, as I feel more comfortable knowing what is being done, and if I screw it up I can't blame anyone but me.

Thanks in advance for any future help.