High HC readings on emissions
headers. They get cold, the O2 sensors get slow,
and your mixture swings wider all the time. HC
comes up at either extreme.
Now I see no mention of having cats. The Jet-Hot
cats that come with the Jet-Hot Y are a joke in
any case, even before they blow out. Cats and a
mixture that stays near center are the best bet
for passing HC.


