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Hey guys!

Recently I received an EPA notice from a cop standing on the side of the road in the city - I should have followed my instincts & ran him over =p

So I have to get an EPA certificate to verify that my exhaust wasn't too loud - however when I had it tested it read 92dBs whereas the legal limit is 90.

My argument was do they not consider systematic & random error, thus give or take 2dBs?

The guy revved it to 4800 (whilst on his phone!) and a part of me kept thinking if he revved slightly over it would also count for the 2dB over. I mean I was able to pass Road worthy with this baby just last year.

More info on the car:

R34 N/A (still on my Ps), no engine mods - all other mods are cosmetic

3.5 piping, 4inch tip

I just don't want to spend MORE money on something so small - plus i love the rumble the current exhaust has

If you have advice OR a stock exhaust I can buy/borrow (or cheap muffler) just to use temporarily for EPA certificate, please comment :glare:

Much appreciated !

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https://www.sau.com.au/forums/topic/324964-epa-exhaust-noise-need-help/
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Roadworthy surprisingly doesnt have anything to do with noise levels and shit like that..

Have you checked your power leels before the exhaust.. I'd think that a 3.5" pipe on an N/A would lose power as it has less back pressure.. Also my advice.. install something to bring the noise level down 2dB and avoid the problem reoccuring..

  • 2 weeks later...
Roadworthy surprisingly doesnt have anything to do with noise levels and shit like that..

Have you checked your power leels before the exhaust.. I'd think that a 3.5" pipe on an N/A would lose power as it has less back pressure.. Also my advice.. install something to bring the noise level down 2dB and avoid the problem reoccuring..

Hey 75c guy lol

The car is actually my first car - and I plan to get rid of it immediately and upgrade when I get off my Ps.

This was more so temporary wheels. So I never really cared about the loss of pressure - If it saved me $800 for the time being

Question. Would getting a custom muffler made (about $140) - keep the piping - cause damage to my transmission due to pressure build up? That's what I was told.. that I would need to get an entire new Cat back

yes but you just want a temporary fix.. but what if you get pulled over again during the time you have the car? Best option is to get the level within the limit required and not have to worry about it anymore..

changing a pipe from catback is still going to cause back pressure anyway.. so i don't see why it would harm your transmission.. you could also look at buying or trading with a member on here for cat back, etc.. someone will want to upgrade their system to 3.5inch and would prob even pay you a bit for the difference..

either way i would get a second opinion on the custom muffler to make sure you're not getting ripped..

I'm also not illiterate or immensely challenged.. just a smart arse.. you posted in the wrong section.. there is a for sale section.. and you said auction to the highest bidder.. also BTW auctions aren't allowed on this forum.. so i was just jks.. thought that was obvious?

Edited by .:: GimpS-R34 ::.
yes but you just want a temporary fix.. but what if you get pulled over again during the time you have the car? Best option is to get the level within the limit required and not have to worry about it anymore..

changing a pipe from catback is still going to cause back pressure anyway.. so i don't see why it would harm your transmission.. you could also look at buying or trading with a member on here for cat back, etc.. someone will want to upgrade their system to 3.5inch and would prob even pay you a bit for the difference..

either way i would get a second opinion on the custom muffler to make sure you're not getting ripped..

I'm also not illiterate or immensely challenged.. just a smart arse.. you posted in the wrong section.. there is a for sale section.. and you said auction to the highest bidder.. also BTW auctions aren't allowed on this forum.. so i was just jks.. thought that was obvious?

i was joking :P

did not intend to insult - sarcasm in my comment too ;)

I have no idea how this site works to be honest lol. Not targeting auction, more so "best price" as i want to sell asap :)

Thanks for your advice.

I actually get pulled over at least twice a month - so I'm hoping to get a permanent change..

But I'm struggling with how much I should get rid of this for and how much I should be expecting for another cat back system :/

Finally found out its a HKS cat back - no idea how much I should be selling it for and what I should be replacing it with.. I'm only good at exterior mods; engine parts have me stumped.

Advice would be greatly appreciated

just borrow someones stock exhaust get it cleared and worry about again in the future plenty off people will be able to help you out.

there is no leniency or couple db over is ok type rule its 90 or less or its fail.

just chuck up a wanted to borrow thread should be easy as

no insult taken.. it's the internet.. you can say as you please i am not phased.. and yeah i picked up at joke of it..

before you follow my advice in your thread and kill it.. just ask for prices.. and also search the forum for HKS exhaust.. see what they sell for.. then if you want to offload it.. drop the price that you're comfortable with.. then get a permanent change.. if you are contstantly getting done and want to avoid it.. or you can look at getting something welded inside possibly to permanently quieten it down..

If you wanna go with the last method i would PM r31nismoid.. he's the expert and will give the best advice as he has been through it all.. He's in melb also and can prob catch him at the vic meetings or something..

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