actright

Someone once told me that when you run your finger here (exhaust tip) and if your finger is brown it means your car is running clean, but if its black then its running dirty.

I was wondering if anyone had any tips to get your car running cleaner, recently i ran the fuel injector cleaner stuff (the one that you put in a full tank) and did a coolent flush. I also recently did an oil change, im going to clean it out and then do the finger test again.

03CoupeV6

I'm not sure that there is any truth in that "brown-clean black-dirty" thing. In every car I've had, the soot from the exhaust was black.

Niko2000TL

black soot in the exhaust is normal, you'll find it in just about any car. now if you're blowing black smoke, then thats bad. if you're worried about the engine running clean, try seafoaming it. theres a few threads going now about it. i just did it, and i feel the difference.

Phrosttz0

black is normal, in fact most honda put out quite a bit of black soot

Costco

I never heard of the brown = clean before but it's regular for it to be black along the tip. What matters is how much soot is on there.... if you run your finger along and it's super thick on the inside, it means your car is running rich. Usually it's because the engine doesn't get up to optimum operating temperature (this does not mean you should warm your car up). You are probably taking too many short trips. If you take 5-10 min. trips to the grocery store, turn off your car and another 5-10 mins. to get back home, then you will accumulate a lot of soot.

Its just carbon buildup. Once in a while I'll just floor it after I get onto the freeway.

01tl4tl

Another vote for the Seafoam treatment, an $8 can of heavy duty carbon buster similar or same as used in the every 15,000 mile $99 fuel injector cleaning service, you suck it into the engine thru an easy access vac line and let sit 15 minutes to help dissolve- then a good freeway blast- normal short freeway blast do not clean the carbon out like people would like to believe.
My oil was really bad after the Seafoam treatment- just as it should have been!
I like Redline SI-1 fuel cleaner and Lucas fuel cleaner , both proven effective in my cars and trucks and race cars
Many of us also like Chevron gas with techron or Union 76
AMPM seems to get a little less mileage per tank