Black "soot" on tailpipe
 

Has any else had a black "soot" on their tailpipe. my exhaust system is stock. My only mod is a CAI. The "soot" was there pre intake.

hu? you mean a rainbow-like-stain??? i do....

If you mean multi- color, then no. It is black and soot like. I have seen it MX-5s 3's (2.0&2.3) . I have asked the dealer no clue. When say rainbow are you talking about over heating the metal?

Every car has it. I've noticed the bigger the pipe the more of if you'll see. I don't know why is it there but it's normal. Just clean it once in a while and don't worry about it.

yup its from heat, the black one ist probably just charcoal, easily cleaned

Mazda's are notorious for running rich. That's why the black soot appears. Especially if you have a Speed3. I can clean mine and have black soot covering the exhaust tip a day later.

Running rich, that makes alot of sense. Thanks

Completely normal.

Every car I've ever driven develops a bit of black soot around the exhaust tip edge.

Mine is pretty rich also, i have a cpe cai , They told me it takes about 2-4
thousand miles for the computer to adjust.

Well I have a speed3 as well and have had the better catback put on but still have the black on tail pipe as well... Clean it one day back the next.

Iv got 400 hundred miles since the cpe cai install, ill post if it starts to lean out
after a few more miles, say a 1,000 or so.