went to take my biannual smog test to renew the registration today and failed, ran too rich and cant figure out why?

ran it to get more than warm enough before showing up for the test, havnt made any changes to the fuel system. still dont know whats wrong. if anyone has tips or checks id gretaly appreciate it before spending the over priced fee of getting the diagnostic.

the test results:
Hydrocarbons max @ 15 mph is 118 ppm/ MINE was 172 FAIL
Hydrocarbons max @ 25 mph is 98 ppm/ MINE was 156 FAIL

CO max @ 15 mph is 0.68%/ MINE was 1.07% FAIL
CO max @ 25 mph is 0.87% / MINE was 0.56% PASS