Today, I was out cleaning up the car after autocrossing yesterday. well, now I have a little problem. Afterwards, I went to start my car and noticed that the "maintanance required" light was flashing before me. Hmmm. I shut the car off immediatly, popped the hood and began inspecting the car. Then as I walked around to the back of the car, I noticed my exhaust had spewed out some of this fun stuff. This is about 10 mins after i turned on the car and it was wet.



i had my mom come out and start my car with me standing behind it, and this crap just dumps out.

i pop the hood again and find this too. there is the same stuff on the hood and a little on the valve cover, but doesn't look like its coming from the valve cover or the header.



i think it may be a bad cat. i noticed it making a little vibrating sound just above 3000RPM for about two weeks, but just thought I may need to re-tighten the bolts. it sounded as though a heat shield was touching the exhaust but quieter.

the exhaust set up is a Mugen 4-2-1 gymkhana header, jdm cat, jdm b-pipe, and Spoon N1 axle back.

thanks

 

sorry for the long post, i was just trying to be clear as possible

 

the water on the ground looks normal to me.....

as your exhaust cools condensation forms in the pipes, and then is spewed when the car is started.....

as far as under hood goes, if you run through water sometimes it can get on the belts and kick it up on the inside of the hood.......

 

The "maintanance required" light is mileage triggered (as in 15000, 300000, etc mile tune ups) so if there is a problem, it wouldnt have caused that light to come on. If anything, it would have triggered your "Check Engine" light to come on. However with regards to spitting black, wet stuff from your exhaust, you said you were cleaning out your car so did you happen to wash your car and maybe spray water up the exhaust pipe? Its possible that if this was done, then its jus the exhaust spitting the water with carbon from inside your exhaust out causing this black wetness. However engine bay-wise, you have me stumped so i cant really offer any input there. Hope this helps.

 

no, no water was used when cleaning the car. i know how sometimes when you run the car hard, it will do it, but i mean it was dumping this stuff.

as for the maint. required light, my car is just about to roll.......gasp...........140,000 miles!!

i just had reason to believe the cat is falling apart

 

alrigt, here is test #2.

i grabbed a charcoal bag that was sitting there in my garage and set it about a foot and a half behind the exhaust like so:



then i tapped the throttle to 4200 RPM and let it go back down to normal idle and shut her off (took 5 seconds) and this is what I got




doesn't look too good

 

bro i had this same situation. i fixed the problem by realizing my O2 sensors werent working correctly, and once i fixed them the problem went away immediately. It has something to do with the O2 sensors/cat/exhaust. but i didn't have any of it on my hood or engine bay, just through the exhaust so i dont know what to say about that part..

https://honda-tech.com/zerothread?id=1480250

 

How is your oil level ?

If the engine is fine, I would personally run it for a while and see if it goes away, maybe you just have a **** load of condensation build up in your exhaust system.

 

A friend of mine had the same problem when his OEM cat took a dump on him. It was actually pretty cool because it would spit flaming chunks of honey comb about 10 feet out of his exhaust.

FWIW he later replaced his o2 sensors also.

 

Same problem happend to me when i had the car in the shop for bout 2 months.
Drove it around for a few days and its gone.