1995 Acura Integra Check engine Light

The only ways to find the reasons for the check engine light is with either a scanner or a jumper wire.
You could purchase a cheap scanner for $30-$50 dollars which would only give you a code. You could go to a shop or dealer to have it diagnosed, it is usually 1 hour labor so $60-$100 depending on the shop. The other alternative is to do it yourself by jumping the ecm located behind the carpet under the glove box and counting the flashes of light at the dashboard. Most people are unsuccesfull when it comes to doing this.
There could be hundreds of different reasons why the light could come on. Literally. Sorry I can't tell you why, but those above where your options.