carbon on back of car

[gt489]

ive been noticing that there is carbon building up on the back of my car. the car has 36xxx miles on it and has the following mods jdm header, comptech air filter, spoon wires and thats it. it doesnt consume oil and the gas mileage is good. normal driving its minimal and wot it obviously gonna be more. it just seems like a lot cause i wash the car everyday that i use it and there seems to be a bit of it there. any ideas? i know the fuel rail was replaced by acura before i got the car.

[Dave_B]

Do you ever see smoke? If so, what color is it? If your really not loosing oil, then it could be fuel.

But it's definitely either fuel, or oil.

[gt489]

its black at wot. im about 99% sure its fuel problem or is it just normal?

[JDM FACTOR]

Are you running any sort of aftermarket exhaust system? Cat removed?

[gt489]

nope. stock cat and exhaust. it does have a jdm itr header

[Dave_B]

What cat? Stock cat won't work with the JDM ITR header as the collector size is different than the OEM unit. That is, if your using a 98 spec header.

[gt489]

idk know im gonna have to take a better look at the cat. its a 98 spec header. i just put the heat shield back on the cat and it looked like a honda cat.

[Dave_B]

Any CEL's? Specifically for O2?

Did this just start happening, or has it been doing it for a while?

[gt489]

no cel. ive only owned the car about a month now

[beastnatch]

If it's a JDM exhaust manifold with OEM USDM catback, then it's probably a test pipe. It's always possible someone put an entire JDM exhaust system on it though.

[gt489]

def has a cat on it

[gt489]

its also has a spoon tb

[Dave_B]

Has the car been tuned ever?

[gt489]

not that im aware of. my friend looked at it last night and thinks its a jdm cat