Q: Changing sensor in 1999 Honda Accord with the check engine light on

Of course. I would try the sensor first. They are cheaper. Realize that oxygen sensor systems are part of a complex computer-driven feedback system. It measures the amount of oxygen in your exhaust, then it gives feedback to your computer and then the computer sends a certain amount of fuel to the fuel injectors so that it runs on a perfect stoichiometric ratio of 14.1 parts air to 1 part gasoline—fuel.

These are very complex systems. Hope that it is the oxygen sensor and not the catalytic converter. It’s very costly if it’s the catalytic converter. There are a lot of other things that could be, too.

You’re going to need a professional mechanic to check that out. You might check the sensor first and if that doesn’t work, I’d say maybe you would call and have them come and inspect the Check Engine Light out for you and replace the oxygen sensor if needed.