just a quick exhaust question

[pieman18]

hey guys

im sure most of u have done what i did on saturday arvo, nothing too serious but i just want some educated opinions

i was at the carwash on satday and it has those small speed humps in and around the bays and stuff, i went over one a bit too quickly, although it was still very slow, and smashed the shit outta my exhaust pipe right on the cat

ever since then i can hear this rattle coming from just under the passenger side where it wouldve connected with the speed hump. i jacked it up to check it yesterday, checked all the bolts on the extractors and joins, gave it a shake and a kick and it seems fine, although i have dinted the cat, and the underside of my car where the cat hit the car, anyway, as i said it seems fine but it still rattles

it only rattles on acceleration, when im in 5th cruizing on a freeway and when i go over sharp bumps in the road or driveways or something

i kind of expected the bolts in the first join to be loose or a small crack or something, but nothing, i thought it may have been the gearbox but its acting the same and the car still pulls hard, im confused

what do u guys reckon?

[yoshimitsu9]

probably cracked the honeycomb formation inside the cat and its all rattling around inside. that would be my best guess

rip awsome skids to blow it all out :p

[--Redwork--]

Yeah... the sounds exactly like you've damaged the internals of the cat...

Worst thing is though... now that its loose, it will get banged around inside and slowly get samaller and harder untill it eventuall blocks your exhaust and kills all the power... your motor will struggle to rev and your car will feel woofull.

Happend to my housemates car not long ago...
Didn't take very long at all to get to the blocking point. maybe 2-3 weeks of day to day driving...

[pieman18]

ahhh, sounds reasonable

so wat should i do?

i have been looking for an excuse to get a new exhaust for a while haha

[Cerby86]

cut the cat out shove a star picket through it ( laterally along the pipe not radially through it) weld it back in. Don't spend any money, don't get absolutely raped by johnny wopper.
If ever get rta'd for the exhaust go to the exhaust place and get a new cat then go to the testing place and laugh!
Or you could move to tassie where we don't have to worry about these things :P

Edit: pull the star picket out before welding the cat back in hahaha

[fatke]

run a straight thru pipe man lol like me

[pieman18]

i dont have the tools to cut and weld the cat off and back on, so would i get the same result from taking the whole exhaust off from the main joint after extractors back to the tip and kind of loosening the broken bit with a star picket and work it out?

would that work?

i have limited knowledge with exhausts, so what is that orange lubricant sorta stuff thats used in the joints? will i need more when i reconnect it?

[Jonny Rochester]

As far as getting work done, exhaust is the cheapest part of a car. So just drive to an exhaust shop and have them look at it, and replace the cat, or replace with a "test pipe" or whatever. It saves alot of trouble.

[pieman18]

run a straight thru pipe man lol like me

haha thats my plan when i get some money

thats why i was secretly hoping it was fucked :hehe:

ill have a look at it over the weekend, see how hard it is to take it off, see if i can poke that shit out, if i dont seem to get anywhere ill take it to an exhaust shop, see what they can do for me

im also intrigued to see how loud a standard silvertop is with relatively no exhaust haha

[Cerby86]

As far as getting work done, exhaust is the cheapest part of a car. So just drive to an exhaust shop and have them look at it, and replace the cat, or replace with a "test pipe" or whatever. It saves alot of trouble.says the man who has done every thing except his exhaust:P


Oh and the paint i suppose hahaha


Look man you could do what i said but i wouldn't, A new cat should cost about $150 ish. Cos your on the mainland you need to at least have the outside (visible) part of the cat there so you don't get raped by the law.
If you don't act like a complete tool you should be able to get an exhaust place to clean out your cat and weld it back in, especially if you explain you are broke. Just remember it is illegal for them to do this so if they do it for you it's a favour so you owe them!
If you can't find someone who will do it, you could get something from a wrecker i suppose. Just look for something in the same diameter pipe and as new as possible!

[Golberg]

Come on people, there is a reason why cars come with cats, and a reason why they should stay.

Just take it to an exhaust shop and get it replaced.

If you get done by the EPA not running a cat its a big fine.

[Jonny Rochester]

I will tell you a secret. I am going to be working at an exhaust shop, tomorrow. Oh the shame.

[Jonny Rochester]

Yes, I doubt a cat on a 4A-GE with slightly oversize exhaust is going to have any effect on performance.

[Cerby86]

hahah nice jonny, which one??

Golberg, I agree with you totally however if he has over about 100,000kms on that cat a piece of straight through pipe will probably clean up the emissions better!

[86coupe]

With any luck, you may have just damaged the heat shield over the top of the cat (if it has one). I had an exhaust rattle that I couldn't find, until I noticed the tack welds on the heat sheild had come loose on one side. Ripped the whole thing off. Problem solved.

[pieman18]

yeah checked that

all the welds are fine as far as i can tell, apart from the dent in the cat and several scratches and scrapes on various bits of the pipes, there is no visible damage to it