Maybe you guys can shed some light on this:I failed 1 part of the test

HC ppm

limit: 65
my reading: 121


everyything else passed with flying colors.I changed the oil ,air filter and pcv before the test.

 

My sons Rustang kept failing on high HC and CO. We found out that someone had gutted the converters. New converters got installed and it passed. Check the O2 sensors, smog pump and smog pump related parts.

 

Try using a can of emmisions cleaner like 104's and change your O2 sensor. Also If your oil level is high it can increase your HC's.

 

Since you didn't list O2 sensor as one of the things you replaced, I'll 2nd that recommendation. But, you didn't really do a "tune-up", so plugs, wires, cap & rotor would also be a good idea.

A misfiring cylinder or leaking injector can also increase HC's.

 

Check your timing as well. A bump in timing can have a big effect on HC's.

 

HC is misfire. Double check timing & do plugs, wires, cap, rotor, and you should be good.