Exhaust issues (loss of power)

[Assault_Cow]

Hey guys.

Got a little issue with my teg :o.

Ok so the other night, i did the stupid thing of rev limiter on cold start (that is, holding it at rev limiter for 2-4seconds only with the engine being started for 30secs or so).

Immediately after doing so, on the highway i could hear an abnormal exhaust noise coming from around my cat/extractor joint area (could not be precise as i am in the car). It sounds like a hiss, or like a constant leak of air, only at 4000rpm and above on WOT. Also noted was roughly a 10-20% decrease in power across the whole rev range.

I immediately thought an exhaust leak/gasket leak. Took it to my exhaust shop, they say 0 leaks.

My whole exhaust setup is roughly 4months old, and the cat is a high flow spec one. So i took one of the exhaust guys for a ride so he could hear the noise. After syphering his attention through the induction noise, normal exhaust note etc etc, i got him to focus on the actual noise i wanted him to listen to. He thinks it could be a blocked cat.

Has anyone had any similar incident on their cars? Or are familiar with a hiss (leaky) noise being produced from around their cat area?


thanks
James

[d15z1SUX]

its your turbo boosting psssssssssssssssssssssttt.

[ACTI0NMAN-1]

how the hell are we supposed to diagnose engine problems with text describing sounds.

Take it to a mechanic.

[[[d a n n y]]]

try resetting the ecu..
see if that helps

[xtercii]

why did you rev the car when it's cold?

[Mr_Dc2aRgh]

it could be a leak on the joint of your exhaust or header

[Assault_Cow]

Its not an engine problem, its an exhaust system problem. The sound is being produced around the cat area of the exhaust.

I reved car to show off in the dirt after work to a friend. A poor decision.

I also suspected a leak of the joint from header to cat, or header to engine block. But the exhaust shop seems to think all checks out.

I am getting it taken apart tuesday to look inside the cat, see if its stuffed internally.


James

[Zilli]

i remember many years ago when the cat on my old mans old xf ute shat itself... it made the most HURRENDOUSLY loud hissing sound! and it just wouldnt move the power loss was so great, but then he had to replace the entire exhaust system as the bits that became dislodged from the cat went through the system into the mufflers...

I highly doubt that you did was the cause of this... whats the difference between you revving the shit out of your car when youve first started it, as opposed to 20 minutes into the trip (on the exhaust). I wouldnt recommend it for the longevity of your motor, but its shouldnt affect ur exhaust

[kazam]

maybe sumthing from the dirt on which i suspect u were doin wheel spins or sumthing on (correct me otherwise) may have flown up and hit and punctured sumthing?

[Assault_Cow]

maybe sumthing from the dirt on which i suspect u were doin wheel spins or sumthing on (correct me otherwise) may have flown up and hit and punctured sumthing?

mmm this is a possibility.

I thought that a cat sitting there at rather cold temperature (it was late night time, very cool), then all of a sudden constant intense heat blown into it might of been the cause for either the material inside to deform, or some type of bad byproduct to form. mmm just a theory, anyways it goes in tomorrow and ill let yous know whats the find.

[Assault_Cow]

cat check out fine. So now i have no idea whats gone wrong, and a lot less power. I might try an ecu reset or something, but thats just clutching at straws. Ideas?

[JasonGilholme]

you'll be surprised what an ECU reset will do.

Check for codes before you go resetting it.

[Assault_Cow]

you'll be surprised what an ECU reset will do.

Check for codes before you go resetting it.

im assuming theres a nifty guide on here?

[JasonGilholme]

:thumbsup:

[Assault_Cow]

just done the ecu check, 0 codes came up, engine light simply stayed on for entire time that car was set to 'on', and turned off as soon as i pulled the jumper pin out. Just did an ecu reset, see if this helps.

Is it worth taking the car to a honda dealer and asking them to identify possible electronic or ecu problems? Or will this be a big waste of money?

ta
James