i have a rather odd question...and that is how to remove the carbon from my exhaust system. i have hooker shorty headers and i removed the cat to put in an exhaust cut out switch and also have a flowmaster 80 series muffler. last summer i put in a couple of chrome exhaust tips and within a matter of a week or two the insides were blackened, and recently my hatch has been having trouble closing and i can smell my exhaust while the cut out is closed, and it is horrible...but i feel as though if i put the cat back in, it wont be much better or clean up anytime soon...anyone have any ideas? its a kinda wierd quesiton and the only thing i could think of to fix this problem is replacing the whole exhaust. looking for any other ideas on it

anyone have any ideas?

Cars ran on E85 have zero carbon buildup in their exhaust

Not sure how to clean the inside of the exhaust out aside from converting but thats a silly reason to do something like that

Does it bother you that much?

it doesnt bother me when my hatch closes...but the motor switch isnt working well and sometimes it wont close, which isnt much of a big deal in itself, except that it wont close for like 2-5 days then one day i'll wake up and its mysteriously closed. but the carbon smell gets in and even with the windows open it seems to just linger, i thought of putting the cat back in but wouldnt that not solve the problem?

Why would you not fix this problem ?

im going to fix it, ive been short on funds and finding things to fix when i get the money pretty much...im actually going to purchase the switch today seeings as how i finally got paid.

Believe me... I fully understand that problem....


I've noticed on my turd camaro that if the hatch is open (when I take the lawn mower over to my moms to cut her yard) that regardless of having the windows down or not, the exhaust smell is very prominent in the cabin. It seems to be just the way the air wraps around these cars that it's prone to suck exhaust in the hatch if it's open in any way.

oh ok...i thought it was just from an excess of carbon buildup throughout my exhaust system because i dont have a cat on it. i just ordered the part today, so i shouldnt have to smell this again for a while, i just wasnt sure if there was some way to clear out the carbon from the exhaust (cuz iknow theres a lot in there from when i had to cut my tail pipes to put on my new exhaust tips) and i figured with all the odd ball things out there, i wouldnt be too surprised if they had some sort of 'put this in the end of your exhaust pipe, run the car in reverse for 20 ft, rev up the motor and then spit on your engine and your exhaust will now be clean' type of product out there

I found driving 60 mph on the freeway for 4 or 5 miles works great to keep my engine free from carbon, so that's my route going home from work. Before just drove the stop and go 45 mph or 55 mph roads to / from work. Carbon built up fast that way; w/ stop n go, excellent gas/oil didn't seem to help carbon too much. Besides, it's more fun to get up to speed even for just a few miles.

what you are essentially asking is how do i douche out my exhaust.
you cant really clean it out like that, but if you are really intent on cleaning it out you could try spraying a hose in it and then run the car semi hard for a while after.

my suggestion would be to get the car running right so that no carbon builds up any more.

Gasoline is made up of carbon, so just by igniting it in your engine you're going to get carbon in your exhaust. You're asking if you can go swimming without getting wet.

Putting a cat on your car like you're supposed to have will go a long way towards cutting down on the smell.

Actually, the chemical reaction in any combustion combines some form of hydrocarbon with O2 and ALWAYS yields H20 and CO2

The carbon build-up is from inefficient combustion and chemicals added to the fuel

LOL 60 moh is fast for you? im just asking, I usually do 70-80 on california roads. but anyways. so a cat delete will make the smell stronger? hmm but you will get more flow without it, everythiing has its ups and downs though right?

as far as getting it out, my buddy always says just take er out and go WOT and that will blow it out.....fact or fiction i dunno.....

Pocket is exactly right - a combustion reaction that is allowed to proceed to completion will oxidize hydrocarbons (in our case for gasoline engines, mainly octane) to produce carbon dioxide and water vapor. These gasses; however, are not responsible for any of the carbon buildup in the exhaust system.
Carbon buildup comes into play because although the aforementioned reaction is the main process that occurs during the combustion cycle, the mixture of air and fuel is never exact enough to allow for a perfectly clean reaction, due slight variations in air/fuel ratio and the presence of other compounds in the gasoline. Therefore, the exhaust gasses contain small amounts of unburned hydrocarbons, oxygen, NOx, carbon monoxide, etc. in addition to the CO2 and H2O. This is where the catalytic converter comes into play. It is responsible for catalyzing further reactions that break down the NOx and unburned hydrocarbons, and oxidize the carbon monoxide to carbon dioxide which is significantly less toxic. So, if you remove your a.i.r. system (which in part helps the cat do its job) and your cat, you dump all of these substances out your exhaust, and it's mainly the unburned hydrocarbons that cause the soot buildup and cause your exhaust to smell like fuel.

If you are concerned about the smell, put the cat back on, and the odors will be dramatically reduced. It will also do a little to help the environment; however, major environmental change isn't going to come from a small (relative to the general auto market) group of enthusiasts modifying their cars, it is the major corporations that have to change their practices before widespread change is realized.