Akrapovic +rear cats delete = disaster

OMRITIME · 09-26-2013, 01:42 AM

So
I have the aa catless dp'
And the akrapovic muffler
Unfortunately its little quiet then the stock
So I removed the secondary cats (straight pipes insted)
I ended with a lot of smoke in the first 10 min of driving (only when cold start)
And nice sound
Also I have a metal ticking sound that appear at 1500-1700 rpm when I press 20% of the pedal like something vibrating at the middle to back of the car
I can hear it on higher gear slow speed when it building pressure

I go to few guys to check it
And everyone said something else
"U need to put back the secondary cats "
" u need replace the pipes because the pipes instead the secondary cats maybe vibrating or too thin "

Anyway I thought I bought the best axle back in the market
And I have this f*****g sound (only when I'm not floor the pedal)

I don't know what to do more
Thinking to get the rear cats back and end it.
Can someone advise

Also I miss the stock muffler it has that pop pop crackle sound.....

enrita · 09-26-2013, 02:13 AM

Normal when catless... Get some high flow cats or resonator

OMRITIME · 09-26-2013, 03:41 AM

Quote:

Originally Posted by enrita

Normal when catless... Get some high flow cats or resonator

Where ????

HighPSI · 09-26-2013, 07:52 AM

vibrant 1792 resonators

/end of thread

whosdady · 09-26-2013, 08:06 AM

Put the stock stuff back on and sell the Akrapovic slip on exhaust to me.

OMRITIME · 09-26-2013, 10:10 AM

Quote:

Originally Posted by HighPSI

vibrant 1792 resonators

/end of thread

U sure?!
And what
Install Tham where the secondary cats was?

HighPSI · 09-26-2013, 10:31 AM

Quote:

Originally Posted by OMRITIME

U sure?!
And what
Install Tham where the secondary cats was?

Yes and yes

I did the same thing as you and as soon as I installed them everything sounded perfect

iturbo_bmw · 09-26-2013, 11:57 AM

I think the smoke your seeing is because your catless and its the gunk burning off or something while ur cars getting warmed up. The metal ticking sound is probably from your wastegates..the wastegate rattle is supposed to be more audible with catless downpipes but nothing wrong with that. if you have a tune (like jb4) you can change some settings to help get rid of that sound. If the sound is too raspy for you then get the resonators described above

09-26-2013, 01:42 AM	#1
OMRITIME Lieutenant 108 Rep 589 Posts Drives: M4 Join Date: May 2010 Location: tel-aviv iTrader: (1)	Akrapovic +rear cats delete = disaster So I have the aa catless dp' And the akrapovic muffler Unfortunately its little quiet then the stock So I removed the secondary cats (straight pipes insted) I ended with a lot of smoke in the first 10 min of driving (only when cold start) And nice sound Also I have a metal ticking sound that appear at 1500-1700 rpm when I press 20% of the pedal like something vibrating at the middle to back of the car I can hear it on higher gear slow speed when it building pressure I go to few guys to check it And everyone said something else "U need to put back the secondary cats " " u need replace the pipes because the pipes instead the secondary cats maybe vibrating or too thin " Anyway I thought I bought the best axle back in the market And I have this f*****g sound (only when I'm not floor the pedal) I don't know what to do more Thinking to get the rear cats back and end it. Can someone advise Also I miss the stock muffler it has that pop pop crackle sound..... __________________ 2008 e92 335 FBO 2011 e92 M3 ZCP DCT 2015 f82 M4 DCT
	Appreciate 0 Tweet Quote

09-26-2013, 02:13 AM	#2
enrita Major General 161 Rep 7,377 Posts Drives: 335i - Big turbos Join Date: Sep 2008 Location: Italian in Sweden iTrader: (0)	Normal when catless... Get some high flow cats or resonator
	Appreciate 0 Quote

09-26-2013, 07:52 AM	#4
HighPSI Banned 9 Rep 280 Posts Drives: E92 335i Join Date: Nov 2012 Location: Toronto iTrader: (0)	vibrant 1792 resonators /end of thread
	Appreciate 0 Quote

09-26-2013, 08:06 AM	#5
whosdady Major 135 Rep 1,075 Posts Drives: 335i Coupe Join Date: Aug 2012 Location: STL iTrader: (10)	Put the stock stuff back on and sell the Akrapovic slip on exhaust to me.
	Appreciate 0 Quote

09-26-2013, 11:57 AM	#8
iturbo_bmw Major 85 Rep 1,099 Posts Drives: 335i, 530i Join Date: Oct 2012 Location: San Jose iTrader: (0)	I think the smoke your seeing is because your catless and its the gunk burning off or something while ur cars getting warmed up. The metal ticking sound is probably from your wastegates..the wastegate rattle is supposed to be more audible with catless downpipes but nothing wrong with that. if you have a tune (like jb4) you can change some settings to help get rid of that sound. If the sound is too raspy for you then get the resonators described above
	Appreciate 0 Quote