Honda Civic 2000 DX, Check Engine Light Becomes On but Does Not Give OBD Code

CEL means engine is not burning properly and it could mean a dozen things. Even without OBD code, you could still solve the mystery by observing the symptoms. Normally symptom is more pronouced at idle. It looks like you might have to do without the help of OBD II. Gather more symptoms.

Buy your own reader. Look at the ELM327 bluetooth reader. It's about $20.

If your check engine light is on the car had a code. To be honest, this sounds like a case of a human error. Luckily, Eric the Car Guy has a video about pulling Honda codes without a scanner.

Watch the video and make sure you are doing it correctly: https://www.youtube.com/watch?v=8M5BaAa6tCM

If the photograph attached is an actual photograph of your car then the OBD port appears to be in two pieces. The blue connector on the right of the photograph should be clipped into the main piece along with the other one already in place on the left.

With only half a loom connected, you are unlikely to see any OBD codes although I believe surprisingly few pins are actually used to transmit fault codes.

The Check Engine Light flashing on doesn't necessarily mean that there is something wrong but it could be a good indicator that something is about to go wrong the only problem here is not knowing when or which part is about to fail. I know the anticipation of possibilities is as much fun as watching paint dry so if I were you I would take the time to at least check each of your cylinders and each Fuel Injector for full spark . You just might catch it before it goes into full fault. Remember: When checking for spark at the coil or at the distributor cap; The line that gives you the strongest electrical flow is usually the line leading to the mis-firing cylinder.