Hi welcome too the forum.

My Tenere also sh*ts fire, has done for the last 50,000 miles. I personally like it, it wakes the car drivers up in the morning. ;-) i dont think it causes any harm as my engine is sweet as a nut and pulls like a freight train....... Literally!

I think its something too do with the air whatsit thingy system. (emissions related i think).

Someone with more knowledge than me should be along soon but i wouldnt worry about it.

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To boldly go where no Tenere has gone before.