car did not pass smogg on 1990 Toyota Tercel

my car did not pass the smogg... the hc was too high what could be the problem...

Asked by for the 1990 Toyota Tercel
There could be a number of things that cause high HC. In most cases HC is related to some type of ignition issue, but could also be related to timing, and also a worn engine. A catalyst that's marginal sometimes won't clean up the exhaust enough and can cause high HC. It's best to have a qualified technician take a look at the problem for a correct diagnosis. There are so many issues that could cause high HC it's best to have someone take a look at variables to narrow it down for you.