the car is a 98 Accord LX 4 cylinder with 70K miles.

Anybody can suggest something?

THe following is what the owner's manual says about it.....

This indicator comes on for a few seconds when you turn the ignition switch ON. If it comes on at any other time, it indicates one of the engine's emissions control systems may have a problem. Even though you may feel no difference in your Honda's performance, it can reduce your vehicle's performance and fuel economy. Take the vehicle to your dealer at your earliest convenience.

If you have recently refueled your Honda, the cause of this indicator coming on could be a loose or missing fuel fill cap. Check the cap and tighten it until it clicks. Replace the fuel cap with a Genuine Honda replacement cap, if it is missing. Tightening the cap will not make the indicator turn off immediately; it takes three driving trips.

If the indicator remains on past three driving trips, or the fuel cap was not loose or missing, have the vehicle checked by the dealer as soon as possible. Drive moderately until the dealer has inspected the problem. Avoid full-throttle acceleration and driving at high speed.

You should also have the dealer inspect your vehicle if this indicator comes on repeatedly, even though it may turn off as you continue driving

 

You'll need to short the service connector and get the code that it's throwing. If you have no idea what I'm talking about, you'll find it all explained if you do a search. Once you have the code, post it & someone will be able to better assist you.

 

Well, I have no clue how to short it. I know where the ecu is located. What do I do next?
Search is not deep enough.

 

Thanks man...

I did it and threw a code 6 and 90...

Fixed them, and reseted the ECU.