MinisterofDOOM wrote:Welcome!
If your CEL is on, stop by your favorite parts store and have them scan for codes. It may well be the O2 sensor but a code check will tell you for sure.
Or just check the codes yourself. It only takes a few seconds to put the ECM (ECCS control module) into the diagnostic test mode, switch the ignition on, and count the flashes of the MIL. Then just look the code(s) up and you're done. It's simple.
The procedure is detailed in section EC of the FSM. You can retrieve the codes yourself in less time than it takes to drive to an auto parts store (unless you live right next door to one, of course). But, after you've done it a couple times, you'll see that it only takes seconds to read the codes out yourself.