I recently purchased a very low mileage (7000 miles) 2003 s2000; see signature below for mods list and info. When I purchased it, it was tuned overly rich, and I knew that, so I expected black soot on everything then. But I just had it retuned by a real pro outfit (car runs GREAT), and it STILL spits soot on everything. I had it about 1 foot from my garage door last night, and ran it for like 10 seconds with the door closed, and this morning I have 2 SOLID black spots on my garage door where the pipes were, haha (after less than 10 seconds! Granted I guess startup enrichment maybe..) Plus the rolling black dust bunnies that now run rampant in my garage. Is this normal?? I mean, its almost as bad as my 2stroke dirt bike!!! Not to mention I still get around 10-12mpg a tank. I do have a semi lead foot, but I do about

 

Get some Krank Vents

 

Mine spits soot all over the rear of my garage as well.

I run mine pretty hard as well but I get ~18mpg. Sounds like your either running very rich or you act like an idiot on the roads getting that low of a mpg

The only time I got near that mpg was when I was on the race track, I got 9mpg NA.

 

a good tune shouldnt spit ANYTHING. try some krank vents in the mean time...

Frankly if it spits like a camel I would check the plugs to make sure they didnt get fouled up with all that gunk...this could be perpetuating your problem, even if you fixed the original source of the problem, fouled plugs could be causing the spitting to continue...

 

When I first start mine up it leaves huge black marks on my garage floor. If you're running a Cat it will be part of your problem as it is changing a lot of your exhaust gases to water vapor.

Also, mine speckles the whole back of my car with black soot while driving and my tuner said this was normal with boosted cars; especially if you're using a Cat.

 

Plugs are less than 100 miles old, so should be good there, and krank vents were on the list, but oil catch can does the same thing, no? So going catless improves on this? I was under the impression it would make it worse without a cat. I have a random technology high flow cat, is that any better? haha. I would go test pipe for sure if it helps with this, but doesnt that change your exhaust note considerably? My exhaust just sounds SOOO good, its perfect, and Im afraid a test pipe will make it sound to harsh.. But thanks for the input guys, I at least know its semi normal, but I need to look into the gas milage thing, then re-visit this.

 

I beleive this may be the majority of my problem actually... because It does still carbon foul plugs 2&3.

https://www.s2ki.com/forums/index.ph...&f=22&t=474769

AEM is "supposed" to be looking into this for me, I sent them a log.

 

Well i put down 315 on a completely stokc comptech setup so you should easily be above it. I love the soot spitting ability because i red line it hard everytime a biker or some lame car feels the need to get up my ass at a light.

 

LOL Spyhuner smokescreen, I love it, hahaha

 

I'm going for the seafoam treatment also, see if that helps.