I have a 95 wrangler 4cyl auto and yesterday it was running fine because I took it the gas station to get a full tank of gas and then I put sta-bil I the ha because it is going to be sitting in the garage for awhile. But today I had to now it because I need to get to the attic and as I put the key and turned it immediately the check engine light went on. It seemed like the engine was having a hard time turning over but I'm not sure because I didn't keep trying to start it because I didn't know what was wrong. What could this be? And how could I fix it?