What could be wrong with my mazda truck?

My check engine light in my 1995 mazda B2300 work truck just recently came on, and since then it has that just pulled up to the gas pump smell after i've been driving. It idles smoothly runs good and does not hesitate from a stop, and gets the same gas mileage. It has a 2.3 liter four-cylinder single overhead cam, eight valves and distributorless ignition. Any ideas?|||My first guess is you have a code set by a faulty O2 sensor and you may have a plugged cat. converter thus the funny smell To be sure of the code that was set you need to have it scanned|||you have a fuel leak somewhere. you may have to check your fuel pressure to make sure your pressure aint dropping. also walk along side the vehicle and see if you can see gas leaking|||have the engine scanned and find out what the codes are...this should point you in the correct direction to fix your truck