BLKSTANGER

So I had to smog my car today as I live in Ca. On the 15 mph test I was 1 ppm away from failing. It was the HC that was high. Everything else was ok and not close to failing. The HC dropped for the 25 mph test.
So what would cause this? Do I just need a tune up or something else? I was thinking that the o2 sensors might be getting lazy. But I don't know what exactly the test result mean or how to diagnose. Someone said to clean the tube that runs from the exhaust to the EGR but I don;t know. Any other ideas?
The car now has 160k on it and is stock. Just changed the oil. Plugs and wires are two years old. No other issues, CELs or any other problems.