Since fitting my de-cat i have(other people behind) have told me that when i change gear(5000rpm +)
the exhaust spits out a flame.

What damage will this cause,if any?
I have a straight through exhaust with de-cat,pipercross panel air filter and have no engine mods.
I will try get a pic sorted of the popping flame.
It has been running like this for more than 8 months now.I have had no running problems apart from the maf sensor,which i sprayed with some sort of electric cleaner and has been fine since.
Oh and she does run a little rich