Originally Posted by DEpointfive0

Lol, TECHNICALLY no HFCs pass CA's smog test...

In any case, HFCs should RARELY if EVER, cause a CEL, since they DO have a car, the exhaust fumes are cleaned enough for the secondary O2 sensors to KNOW the air has been cleaned.
Also, if you get a CEL, my money is on having an exhaust leak from header to cat. That's where 99.99999% of CELs come from with install of HFCs