Cereal, I don't know if you would agree with this but I have been told that even if the headers are standard this problem can occur with a more open cat and silencer system. The theory is that with less restriction the gasses flow more freely and, under certain circumstances the temperature of the cat may drop too low for it to "light off".

What do you think?

If you can find a link to that thread I would be very interested to read it.

Peter

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