i just noticed today that there is a patch of black dots that look like charcoal marks all over. The marks are on the concrete are right behind where my exhaust sits. I have watched as my car start up and i don't see any fumes or anything sputtering out... what might be going on?

I am running a stock em1 exhaust, there is a layer of black soot under the tip and canister.... are these oil deposits?

all help will be greatly appreciated

 

its prolly water mixing with the carbon in the exhuast. any oil would prolly burn b4 it got to the end of the exhaust

 

prolly fuel, you didnt state what car you have, but if you drive it hard and hit vtec alot then youll see those black dots appear

 

agreed especially if your not running a cat

 

I drive a 00 ej6, stock motor with only cai and what the original owner called "custom piping" w/ an em1 exhaust. I rarely drive it hard, its not much to play with but i'll check it out this week and see if there's more build up

Would the large build up of black soot inside/around/and under the exhaust be the carbon?

 

you mean em1 muffler? right,

i agree with c1 sleeper,

 

Your car is running too rich, I have the EXACT same problem except mine is 10x worse.

 

yes muffler, my bad


so the carbon is the result of running rich.....? what can be done about it?

 

I am not sure about the carbon but I know your car is running rich. I dunno how to solve that problem but a tune up wouldnt hurt things.

Mine is runny REALLY rich, as in 12mpg rich. I have a notion its the ECU causing the problems so im waiting on a 99-00 replacement ECU.

 

i believe it will also act that way once the catalyst starts to break down, but i could be wrong. just remember that a lil water is normal...all combustion yields CO2 + H2O + N2

 

what can be done to fix my problem of running rich?

 

Do you have a CEL? The primary O2 sensor monitors the fuel mixture.

 

no CEL... if my O2 sensor went bad would it cause the CEL not to come on in this situation?

 

read this thread https://honda-tech.com/forums/honda-civic-del-sol-1992-2000-1/%2450-cash-paypal-person-who-solves-my-mpg-problem-edit-tested-fuel-pressure-2554039/ i was getting like 16mpg and eventually we figured out it was the injectors. But the thread has like 300 something posts and covers just about anything that could cause a rich condition. What is your mpg. If you are getting good mpg i wouldn't worry about it. But these guys are right usually the black dots indicate a rich condition oil is usually fumes by the times it gets out the exhaust.

 

not always the cel is primarily triggered when the heating element goes bad it can still send readings which are incorrect but not throw a cel.

 

Thanks i'll read through it. I haven't clocked my mpg lately and wont be able to for a while, wont be driving for the next 2 months,broke my arm last week. I'm going to get as much done to my car during that time.