P0133 on 1998 Ford Contour

My check engine light keeps coming on and the error I received was P0133. I know this is about the oxygen sensor. I can't replace it myself, my question is...do I have to take it to a dealership to do this? Does anyone know about how much this might cost? I just had to pay $250 for new spark plugs and wires because of a misfire a month ago. I can't pass Texas inspection with the engine light on and it won't stay off. Any suggestions? Thanks!

Sorry to tell you this, but you really got ripped off on the spark plugs and wire set. This could've been done for under $50 if you installed it yourself.

If you have a p0133, check for an exhaust leak. Check the flanges/gaskets at the muffler and catalyst. If it's just the gasket, Monroe can fix it for less than $50 if you don't have the tools or knowledge to do it yourself. No need to take it to the dealer. If you end up replacing the O2 sensor, I recommend using a dealer part instead of aftermarket.