does catback exhaust cause codes

06RedGoat · 05-20-2008, 12:27 PM

I have the vishnu exhaust and about to install.

I am pretty sure it removes a set of cats. Wont this cause a code?

kitw · 05-20-2008, 12:54 PM

No. The secondary cats are after the 2nd 02 sensors.

emjei · 05-20-2008, 01:14 PM

What about warranty issues

akack79 · 05-20-2008, 01:21 PM

Quote:

Originally Posted by emjei

What about warranty issues

Warranty would go bye-bye.

Amir87 · 05-20-2008, 01:24 PM

Cat-back should be fine with warranty. It's the downpipes that will void your warranty based on what I've seen on these forums.

I only have mufflers (axle-back) and dealer could care less.

ZJP · 05-20-2008, 01:28 PM

Yeah but if its a downpipe-back exhaust which normally eliminates the 2ndary cats, they could be pricks about it and deny any warranty work.

Although with the numerous threads on here about warranties and modding, I was under the impression that BMW needs to prove that the part caused the problem in the first place.

scottp999 · 05-20-2008, 02:00 PM

I got a limp mode after installing a catback. It was within the first 10 miles of driving it. I was able to repeat it. I believe that the better flow caused the Air/Fuel ratios to go a little out of wack and the car needed a little time to adapt. It has never pone limp since (many months).

emjei · 05-20-2008, 04:03 PM

I only have mufflers (axle-back) and dealer could care less.[/QUOTE]

This would be only for sound purpose ???? or does it add HP ???

Amir87 · 05-20-2008, 04:13 PM

Quote:

Originally Posted by emjei

I only have mufflers (axle-back) and dealer could care less.

Quote:

Originally Posted by emjei

This would be only for sound purpose ???? or does it add HP ???

It's only for sound, no performance to be gained from just mufflers.

emjei · 05-20-2008, 05:28 PM

Quote:

Originally Posted by Amir87

It's only for sound, no performance to be gained from just mufflers.

Does it change the sound to more agresive.....which muffler ??

faze335i · 05-20-2008, 05:51 PM

Quote:

Originally Posted by Amir87

It's only for sound, no performance to be gained from just mufflers.

Does that mean with Dinan free flow exhaust theres no performance gain at all its only for sound purpose???

akack79 · 05-20-2008, 05:51 PM

Quote:

Originally Posted by emjei

Does it change the sound to more agresive.....which muffler ??

Borla (w/o 2nd cat delete piping)
Bastuck
Eisenmann
Dinan

FYI, there's a sticky up top where you can listen to the different exhausts.

EastCoast335i · 05-20-2008, 06:08 PM

I think everyone is forgetting that installing an aftermarket exhaust cat-back or just mufflers you would be eliminating the flapper valve. Wouldnt this throw codes? When its disconnected it throws codes.

san~man · 05-20-2008, 08:59 PM

Quote:

Originally Posted by EastCoast335i

I think everyone is forgetting that installing an aftermarket exhaust cat-back or just mufflers you would be eliminating the flapper valve. Wouldnt this throw codes? When its disconnected it throws codes.

Disconnecting the part in the trunk does, plugging the line under the rear end doesn't.

emjei · 05-20-2008, 09:12 PM

Quote:

Originally Posted by san~man

Disconnecting the part in the trunk does, plugging the line under the rear end doesn't.

Guys you are now talking chinese to me .......?????????????????

StarrDlux · 05-20-2008, 09:16 PM

disconnecting a circuit causes a SHORT TO OPEN code to log many times.

unplugging any vac line while the car is on will cause EVAP flow issues (like the gas cap beign loose).

turn car off; get a 1/8th" piece of tubing and a 1/8" male to male barbed tube and plug that. takes two seconds to install and two seconds to take off when you realize (sedan) it doesn't really sound any different.

on turbo motors the backpressure of the turbo exceeds any backpressure of the exhaust. N/A cars could generate more low end torque efficiency but no way on turbo cars. Turbo's function on pressure differential. less backpressure always better given the backpressure by the turbo's themselves. They are quite small if you haven't looked.

E92Pilot · 05-20-2008, 11:04 PM

Quote:

Originally Posted by san~man

Disconnecting the part in the trunk does, plugging the line under the rear end doesn't.

All I did was just unplug the vac line that controls the solenoid for the flapper valve in the exhaust. No codes and the flapper is open 24/7. I'd like to know who named it the "golf tee" mod....

EastCoast335i · 05-22-2008, 07:49 PM

Quote:

Originally Posted by san~man

Disconnecting the part in the trunk does, plugging the line under the rear end doesn't.

Cool thanks

I wasnt sure if the removal of the valve would throw codes. But since you say that disconneting the line (which would be the case with an after market exhaust) doesn't throw a code... I think my next major mod will be AE exhaust once they come out with a quad tip version

05-20-2008, 12:27 PM	#1
06RedGoat Second Lieutenant 20 Rep 249 Posts Drives: Sparkling Graphite 335i Join Date: Apr 2008 Location: Hagerstown, Maryland iTrader: (3)	does catback exhaust cause codes I have the vishnu exhaust and about to install. I am pretty sure it removes a set of cats. Wont this cause a code?
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05-20-2008, 12:54 PM	#2
kitw Colonel 471 Rep 2,991 Posts Drives: F91 M8, 991.2 GT3 Join Date: Jun 2007 Location: Bay Area, CA iTrader: (20)	No. The secondary cats are after the 2nd 02 sensors.
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05-20-2008, 01:14 PM	#3
emjei Captain 73 Rep 821 Posts Drives: 08 BMW M3 Coupe Join Date: Apr 2007 Location: Puerto Rico USA iTrader: (3)	What about warranty issues
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05-20-2008, 01:24 PM	#5
Amir87 Gruppe Titan 262 Rep 2,839 Posts Drives: 08 E92 SG/Coral Join Date: Sep 2007 Location: NC iTrader: (37) Garage List 2008 E92 335i [10.00]	Cat-back should be fine with warranty. It's the downpipes that will void your warranty based on what I've seen on these forums. I only have mufflers (axle-back) and dealer could care less. __________________
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05-20-2008, 01:28 PM	#6
ZJP Lieutenant Colonel 127 Rep 1,759 Posts Drives: F10 535xi / B6 S4 Join Date: Jan 2008 Location: LI, NY iTrader: (7)	Yeah but if its a downpipe-back exhaust which normally eliminates the 2ndary cats, they could be pricks about it and deny any warranty work. Although with the numerous threads on here about warranties and modding, I was under the impression that BMW needs to prove that the part caused the problem in the first place.
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05-20-2008, 02:00 PM	#7
scottp999 Brigadier General 133 Rep 4,764 Posts Drives: 4runner SR5 Join Date: Mar 2007 Location: MD iTrader: (2) Garage List 2007 BMW 335 [9.00]	I got a limp mode after installing a catback. It was within the first 10 miles of driving it. I was able to repeat it. I believe that the better flow caused the Air/Fuel ratios to go a little out of wack and the car needed a little time to adapt. It has never pone limp since (many months).
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05-20-2008, 04:03 PM	#8
emjei Captain 73 Rep 821 Posts Drives: 08 BMW M3 Coupe Join Date: Apr 2007 Location: Puerto Rico USA iTrader: (3)	I only have mufflers (axle-back) and dealer could care less.[/QUOTE] This would be only for sound purpose ???? or does it add HP ???
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05-20-2008, 06:08 PM	#13
EastCoast335i Colonel 95 Rep 2,160 Posts Drives: 2015 X5 \| 2008 335i Join Date: Sep 2007 Location: NJ iTrader: (4)	I think everyone is forgetting that installing an aftermarket exhaust cat-back or just mufflers you would be eliminating the flapper valve. Wouldnt this throw codes? When its disconnected it throws codes.
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05-20-2008, 09:16 PM	#16
StarrDlux Pussycat's Meow 9 Rep 682 Posts Drives: '08 335i montego \| Stock Join Date: May 2008 Location: Midtown (Altanta) iTrader: (0)	disconnecting a circuit causes a SHORT TO OPEN code to log many times. unplugging any vac line while the car is on will cause EVAP flow issues (like the gas cap beign loose). turn car off; get a 1/8th" piece of tubing and a 1/8" male to male barbed tube and plug that. takes two seconds to install and two seconds to take off when you realize (sedan) it doesn't really sound any different. on turbo motors the backpressure of the turbo exceeds any backpressure of the exhaust. N/A cars could generate more low end torque efficiency but no way on turbo cars. Turbo's function on pressure differential. less backpressure always better given the backpressure by the turbo's themselves. They are quite small if you haven't looked. __________________ 2008 335i montego \| stock 2002 A4 1.8TQS \| APR 1+ 1990 VW Corrado \| Stage 4 by SNS
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